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* [Tarantool-patches] [PATCH v1 0/8] Rework standard function
@ 2021-11-11 10:45 Mergen Imeev via Tarantool-patches
  2021-11-11 10:45 ` [Tarantool-patches] [PATCH v1 1/8] sql: refactor ABS() funcion Mergen Imeev via Tarantool-patches
                   ` (8 more replies)
  0 siblings, 9 replies; 15+ messages in thread
From: Mergen Imeev via Tarantool-patches @ 2021-11-11 10:45 UTC (permalink / raw)
  To: kyukhin; +Cc: tarantool-patches

This patch refactors all non-aggregate standard functions and makes these
functions work according to ANSI rules, if it is possible. However, the ANSI
specific syntax for these functions will be presented later.

https://github.com/tarantool/tarantool/issues/4145
https://github.com/tarantool/tarantool/tree/imeevma/gh-4145-rework-sql-built-in-funcs

Mergen Imeev (8):
  sql: refactor ABS() funcion
  sql: rework CHAR_LENGTH() function
  sql: refactor UPPER() and LOWER() functions
  sql: refactor NULLIF() function
  sql: rework TRIM() function
  sql: rework POSITION() function
  sql: rework SUBSTR() function
  sql: refactor LIKE() function

 src/box/sql/func.c             | 1143 +++++++++++++++-----------------
 test/sql-tap/badutf1.test.lua  |   81 +--
 test/sql-tap/func.test.lua     |   16 +-
 test/sql-tap/func2.test.lua    |  150 ++---
 test/sql-tap/func3.test.lua    |   10 +-
 test/sql-tap/position.test.lua |   80 ++-
 test/sql-tap/substr.test.lua   |  121 +++-
 7 files changed, 791 insertions(+), 810 deletions(-)

-- 
2.25.1


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [Tarantool-patches] [PATCH v1 1/8] sql: refactor ABS() funcion
  2021-11-11 10:45 [Tarantool-patches] [PATCH v1 0/8] Rework standard function Mergen Imeev via Tarantool-patches
@ 2021-11-11 10:45 ` Mergen Imeev via Tarantool-patches
  2021-11-11 10:45 ` [Tarantool-patches] [PATCH v1 2/8] sql: rework CHAR_LENGTH() function Mergen Imeev via Tarantool-patches
                   ` (7 subsequent siblings)
  8 siblings, 0 replies; 15+ messages in thread
From: Mergen Imeev via Tarantool-patches @ 2021-11-11 10:45 UTC (permalink / raw)
  To: kyukhin; +Cc: tarantool-patches

Part of #4145
---
 src/box/sql/func.c | 83 +++++++++++++++++-----------------------------
 1 file changed, 30 insertions(+), 53 deletions(-)

diff --git a/src/box/sql/func.c b/src/box/sql/func.c
index 0cf17572b..dbeb38bee 100644
--- a/src/box/sql/func.c
+++ b/src/box/sql/func.c
@@ -232,6 +232,32 @@ step_group_concat(struct sql_context *ctx, int argc, struct Mem *argv)
 		ctx->is_aborted = true;
 }
 
+/** Implementations of the ABS() function. */
+static void
+func_abs_int(struct sql_context *ctx, int argc, struct Mem *argv)
+{
+	assert(argc == 1);
+	(void)argc;
+	struct Mem *arg = &argv[0];
+	if (mem_is_null(arg))
+		return;
+	assert(mem_is_int(arg));
+	uint64_t u = mem_is_uint(arg) ? arg->u.u : (uint64_t)-arg->u.i;
+	mem_set_uint(ctx->pOut, u);
+}
+
+static void
+func_abs_double(struct sql_context *ctx, int argc, struct Mem *argv)
+{
+	assert(argc == 1);
+	(void)argc;
+	struct Mem *arg = &argv[0];
+	if (mem_is_null(arg))
+		return;
+	assert(mem_is_double(arg));
+	mem_set_double(ctx->pOut, arg->u.r < 0 ? -arg->u.r : arg->u.r);
+}
+
 static const unsigned char *
 mem_as_ustr(struct Mem *mem)
 {
@@ -395,57 +421,6 @@ lengthFunc(struct sql_context *context, int argc, struct Mem *argv)
 	}
 }
 
-/*
- * Implementation of the abs() function.
- *
- * IMP: R-23979-26855 The abs(X) function returns the absolute value of
- * the numeric argument X.
- */
-static void
-absFunc(struct sql_context *context, int argc, struct Mem *argv)
-{
-	assert(argc == 1);
-	UNUSED_PARAMETER(argc);
-	switch (sql_value_type(&argv[0])) {
-	case MP_UINT: {
-		sql_result_uint(context, mem_get_uint_unsafe(&argv[0]));
-		break;
-	}
-	case MP_INT: {
-		int64_t value = mem_get_int_unsafe(&argv[0]);
-		assert(value < 0);
-		sql_result_uint(context, -value);
-		break;
-	}
-	case MP_NIL:{
-			/* IMP: R-37434-19929 Abs(X) returns NULL if X is NULL. */
-			sql_result_null(context);
-			break;
-		}
-	case MP_BOOL:
-	case MP_BIN:
-	case MP_EXT:
-	case MP_ARRAY:
-	case MP_MAP: {
-		diag_set(ClientError, ER_INCONSISTENT_TYPES, "number",
-			 mem_str(&argv[0]));
-		context->is_aborted = true;
-		return;
-	}
-	default:{
-			/*
-			 * Abs(X) returns 0.0 if X is a string or blob
-			 * that cannot be converted to a numeric value.
-			 */
-			double rVal = mem_get_double_unsafe(&argv[0]);
-			if (rVal < 0)
-				rVal = -rVal;
-			sql_result_double(context, rVal);
-			break;
-		}
-	}
-}
-
 /**
  * Implementation of the position() function.
  *
@@ -1930,8 +1905,10 @@ struct sql_func_definition {
  * function should be defined in succession.
  */
 static struct sql_func_definition definitions[] = {
-	{"ABS", 1, {FIELD_TYPE_INTEGER}, FIELD_TYPE_INTEGER, absFunc, NULL},
-	{"ABS", 1, {FIELD_TYPE_DOUBLE}, FIELD_TYPE_DOUBLE, absFunc, NULL},
+	{"ABS", 1, {FIELD_TYPE_INTEGER}, FIELD_TYPE_INTEGER, func_abs_int,
+	 NULL},
+	{"ABS", 1, {FIELD_TYPE_DOUBLE}, FIELD_TYPE_DOUBLE, func_abs_double,
+	 NULL},
 	{"AVG", 1, {FIELD_TYPE_INTEGER}, FIELD_TYPE_INTEGER, step_avg, fin_avg},
 	{"AVG", 1, {FIELD_TYPE_DOUBLE}, FIELD_TYPE_DOUBLE, step_avg, fin_avg},
 	{"CHAR", -1, {FIELD_TYPE_INTEGER}, FIELD_TYPE_STRING, charFunc, NULL},
-- 
2.25.1


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [Tarantool-patches] [PATCH v1 2/8] sql: rework CHAR_LENGTH() function
  2021-11-11 10:45 [Tarantool-patches] [PATCH v1 0/8] Rework standard function Mergen Imeev via Tarantool-patches
  2021-11-11 10:45 ` [Tarantool-patches] [PATCH v1 1/8] sql: refactor ABS() funcion Mergen Imeev via Tarantool-patches
@ 2021-11-11 10:45 ` Mergen Imeev via Tarantool-patches
  2021-11-11 10:45 ` [Tarantool-patches] [PATCH v1 3/8] sql: refactor UPPER() and LOWER() functions Mergen Imeev via Tarantool-patches
                   ` (6 subsequent siblings)
  8 siblings, 0 replies; 15+ messages in thread
From: Mergen Imeev via Tarantool-patches @ 2021-11-11 10:45 UTC (permalink / raw)
  To: kyukhin; +Cc: tarantool-patches

The CHAR_LENGTH() and CHARACTER_LENGTH() functions now use ICU functions
to determine the length of a string.

Part of #4145

@TarantoolBot document
Title: Invalid UTF-8 values and ICU

Invalid UTF-8 values may be handled differently depending on the ICU
version. For example, for this request:
```
SELECT CHAR_LENGTH(CAST(x'f0808080' AS STRING));
```

On `centos 7` with `libicu-devel-50.2-4.el7_7.x86_64` the result will
be:
```
tarantool> box.execute([[SELECT CHAR_LENGTH(CAST(x'f0808080' AS STRING));]])
---
- metadata:
  - name: COLUMN_1
    type: integer
  rows:
  - [1]
...
```

On `ubuntu 20.04` with `libicu-dev` version `66.1-2ubuntu2` the result
will be:
```
tarantool> box.execute([[SELECT CHAR_LENGTH(CAST(x'f0808080' AS STRING));]])
---
- metadata:
  - name: COLUMN_1
    type: integer
  rows:
  - [4]
...
```
---
 src/box/sql/func.c            | 26 +++++++++++++++++++---
 test/sql-tap/badutf1.test.lua | 42 +----------------------------------
 test/sql-tap/func3.test.lua   | 10 ++++-----
 3 files changed, 28 insertions(+), 50 deletions(-)

diff --git a/src/box/sql/func.c b/src/box/sql/func.c
index dbeb38bee..bc7a1fedd 100644
--- a/src/box/sql/func.c
+++ b/src/box/sql/func.c
@@ -258,6 +258,26 @@ func_abs_double(struct sql_context *ctx, int argc, struct Mem *argv)
 	mem_set_double(ctx->pOut, arg->u.r < 0 ? -arg->u.r : arg->u.r);
 }
 
+/** Implementation of the CHAR_LENGTH() function. */
+static void
+func_char_length(struct sql_context *ctx, int argc, struct Mem *argv)
+{
+	assert(argc == 1);
+	(void)argc;
+	struct Mem *arg = &argv[0];
+	if (mem_is_null(arg))
+		return;
+	assert(mem_is_str(arg) && arg->n >= 0);
+	uint32_t len = 0;
+	int offset = 0;
+	while (offset < arg->n) {
+		UChar32 c;
+		U8_NEXT((uint8_t *)arg->z, offset, arg->n, c);
+		++len;
+	}
+	mem_set_uint(ctx->pOut, len);
+}
+
 static const unsigned char *
 mem_as_ustr(struct Mem *mem)
 {
@@ -1912,8 +1932,8 @@ static struct sql_func_definition definitions[] = {
 	{"AVG", 1, {FIELD_TYPE_INTEGER}, FIELD_TYPE_INTEGER, step_avg, fin_avg},
 	{"AVG", 1, {FIELD_TYPE_DOUBLE}, FIELD_TYPE_DOUBLE, step_avg, fin_avg},
 	{"CHAR", -1, {FIELD_TYPE_INTEGER}, FIELD_TYPE_STRING, charFunc, NULL},
-	{"CHAR_LENGTH", 1, {FIELD_TYPE_STRING}, FIELD_TYPE_INTEGER, lengthFunc,
-	 NULL},
+	{"CHAR_LENGTH", 1, {FIELD_TYPE_STRING}, FIELD_TYPE_INTEGER,
+	 func_char_length, NULL},
 	{"COALESCE", -1, {FIELD_TYPE_ANY}, FIELD_TYPE_SCALAR, sql_builtin_stub,
 	 NULL},
 	{"COUNT", 0, {}, FIELD_TYPE_INTEGER, step_count, fin_count},
@@ -1957,7 +1977,7 @@ static struct sql_func_definition definitions[] = {
 	{"LEAST", -1, {FIELD_TYPE_STRING}, FIELD_TYPE_STRING, minmaxFunc, NULL},
 	{"LEAST", -1, {FIELD_TYPE_SCALAR}, FIELD_TYPE_SCALAR, minmaxFunc, NULL},
 
-	{"LENGTH", 1, {FIELD_TYPE_STRING}, FIELD_TYPE_INTEGER, lengthFunc,
+	{"LENGTH", 1, {FIELD_TYPE_STRING}, FIELD_TYPE_INTEGER, func_char_length,
 	 NULL},
 	{"LENGTH", 1, {FIELD_TYPE_VARBINARY}, FIELD_TYPE_INTEGER, lengthFunc,
 	 NULL},
diff --git a/test/sql-tap/badutf1.test.lua b/test/sql-tap/badutf1.test.lua
index b25436186..ce8354840 100755
--- a/test/sql-tap/badutf1.test.lua
+++ b/test/sql-tap/badutf1.test.lua
@@ -1,6 +1,6 @@
 #!/usr/bin/env tarantool
 local test = require("sqltester")
-test:plan(23)
+test:plan(19)
 
 --!./tcltestrunner.lua
 -- 2007 May 15
@@ -253,26 +253,6 @@ test:do_test(
 
 test:do_test(
     "badutf-3.5",
-    function()
-        return test:execsql2("SELECT length('\x61\xc0\x80\x80\x80\x80\x80\x80\x80\x80\x80\x80') AS x")
-    end, {
-        -- <badutf-3.5>
-        "X", 12
-        -- </badutf-3.5>
-    })
-
-test:do_test(
-    "badutf-3.6",
-    function()
-        return test:execsql2("SELECT length('\xc0\x80\x80\x80\x80\x80\x80\x80\x80\x80\x80') AS x")
-    end, {
-        -- <badutf-3.6>
-        "X", 11
-        -- </badutf-3.6>
-    })
-
-test:do_test(
-    "badutf-3.7",
     function()
         return test:execsql2("SELECT length('\x80\x80\x80\x80\x80\x80\x80\x80\x80\x80') AS x")
     end, {
@@ -281,26 +261,6 @@ test:do_test(
         -- </badutf-3.7>
     })
 
-test:do_test(
-    "badutf-3.8",
-    function()
-        return test:execsql2("SELECT length('\x80\x80\x80\x80\x80\xf0\x80\x80\x80\x80') AS x")
-    end, {
-        -- <badutf-3.8>
-        "X", 7
-        -- </badutf-3.8>
-    })
-
-test:do_test(
-    "badutf-3.9",
-    function()
-        return test:execsql2("SELECT length('\x80\x80\x80\x80\x80\xf0\x80\x80\x80\xff') AS x")
-    end, {
-        -- <badutf-3.9>
-        "X", 7
-        -- </badutf-3.9>
-    })
-
 test:do_test(
     "badutf-4.1",
     function()
diff --git a/test/sql-tap/func3.test.lua b/test/sql-tap/func3.test.lua
index 8d6268bb7..32c807103 100755
--- a/test/sql-tap/func3.test.lua
+++ b/test/sql-tap/func3.test.lua
@@ -1,6 +1,6 @@
 #!/usr/bin/env tarantool
 local test = require("sqltester")
-test:plan(35)
+test:plan(33)
 
 --!./tcltestrunner.lua
 -- 2010 August 27
@@ -294,11 +294,9 @@ suits[2] = {str = '\x80', len = 1}
 suits[3] = {str = '\x61\x62\x63', len = 3}
 suits[4] = {str = '\x7f\x80\x81', len = 3}
 suits[5] = {str = '\x61\xc0', len = 2}
-suits[6] = {str = '\x61\xc0\x80\x80\x80\x80\x80\x80\x80\x80\x80\x80', len = 12}
-suits[7] = {str = '\xc0\x80\x80\x80\x80\x80\x80\x80\x80\x80\x80', len = 11}
-suits[8] = {str = '\x80\x80\x80\x80\x80\x80\x80\x80\x80\x80', len = 10}
-suits[9] = {str = '\x80\x80\x80\x80\x80\xf0\x80\x80\x80\x80', len = 7}
-suits[10] = {str = '\x80\x80\x80\x80\x80\xf0\x80\x80\x80\xff', len = 7}
+suits[6] = {str = '\x80\x80\x80\x80\x80\x80\x80\x80\x80\x80', len = 10}
+suits[7] = {str = '\x80\x80\x80\x80\x80\xf0\x90\x80\x80\x80', len = 7}
+suits[8] = {str = '\x80\x80\x80\x80\x80\xf0\x90\x80\x80\xff', len = 7}
 
 for k,v in pairs(suits) do
     test:do_execsql_test(
-- 
2.25.1


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [Tarantool-patches] [PATCH v1 3/8] sql: refactor UPPER() and LOWER() functions
  2021-11-11 10:45 [Tarantool-patches] [PATCH v1 0/8] Rework standard function Mergen Imeev via Tarantool-patches
  2021-11-11 10:45 ` [Tarantool-patches] [PATCH v1 1/8] sql: refactor ABS() funcion Mergen Imeev via Tarantool-patches
  2021-11-11 10:45 ` [Tarantool-patches] [PATCH v1 2/8] sql: rework CHAR_LENGTH() function Mergen Imeev via Tarantool-patches
@ 2021-11-11 10:45 ` Mergen Imeev via Tarantool-patches
  2021-11-11 10:45 ` [Tarantool-patches] [PATCH v1 4/8] sql: refactor NULLIF() function Mergen Imeev via Tarantool-patches
                   ` (5 subsequent siblings)
  8 siblings, 0 replies; 15+ messages in thread
From: Mergen Imeev via Tarantool-patches @ 2021-11-11 10:45 UTC (permalink / raw)
  To: kyukhin; +Cc: tarantool-patches

Part of #4145
---
 src/box/sql/func.c | 118 +++++++++++++++++++++------------------------
 1 file changed, 55 insertions(+), 63 deletions(-)

diff --git a/src/box/sql/func.c b/src/box/sql/func.c
index bc7a1fedd..88830fd78 100644
--- a/src/box/sql/func.c
+++ b/src/box/sql/func.c
@@ -278,6 +278,59 @@ func_char_length(struct sql_context *ctx, int argc, struct Mem *argv)
 	mem_set_uint(ctx->pOut, len);
 }
 
+/** Implementation of the UPPER() and LOWER() functions. */
+static void
+func_lower_upper(struct sql_context *ctx, int argc, struct Mem *argv)
+{
+	assert(argc == 1);
+	(void)argc;
+	struct Mem *arg = &argv[0];
+	if (mem_is_null(arg))
+		return;
+	assert(mem_is_str(arg) && arg->n >= 0);
+	if (arg->n == 0)
+		return mem_set_str0_static(ctx->pOut, "");
+	const char *str = arg->z;
+	int32_t len = arg->n;
+	struct sql *db = sql_get();
+	char *res = sqlDbMallocRawNN(db, len);
+	if (res == NULL) {
+		ctx->is_aborted = true;
+		return;
+	}
+	int32_t size = sqlDbMallocSize(db, res);
+	assert(size >= len);
+	UErrorCode status = U_ZERO_ERROR;
+	const char *locale = NULL;
+	if (ctx->coll != NULL && ctx->coll->type == COLL_TYPE_ICU) {
+		locale = ucol_getLocaleByType(ctx->coll->collator,
+					      ULOC_VALID_LOCALE, &status);
+	}
+	UCaseMap *cm = ucasemap_open(locale, 0, &status);
+	assert(cm != NULL);
+	assert(ctx->func->def->name[0] == 'U' ||
+	       ctx->func->def->name[0] == 'L');
+	bool is_upper = ctx->func->def->name[0] == 'U';
+	int32_t new_len =
+		is_upper ?
+		ucasemap_utf8ToUpper(cm, res, size, str, len, &status) :
+		ucasemap_utf8ToLower(cm, res, size, str, len, &status);
+	if (new_len > size) {
+		res = sqlDbRealloc(db, res, new_len);
+		if (db->mallocFailed != 0) {
+			ctx->is_aborted = true;
+			return;
+		}
+		status = U_ZERO_ERROR;
+		if (is_upper)
+			ucasemap_utf8ToUpper(cm, res, size, str, len, &status);
+		else
+			ucasemap_utf8ToLower(cm, res, size, str, len, &status);
+	}
+	ucasemap_close(cm);
+	mem_set_str_allocated(ctx->pOut, res, new_len);
+}
+
 static const unsigned char *
 mem_as_ustr(struct Mem *mem)
 {
@@ -791,67 +844,6 @@ contextMalloc(struct sql_context *context, i64 nByte)
 	return z;
 }
 
-/*
- * Implementation of the upper() and lower() SQL functions.
- */
-
-#define ICU_CASE_CONVERT(case_type)                                            \
-static void                                                                    \
-case_type##ICUFunc(sql_context *context, int argc, struct Mem *argv)           \
-{                                                                              \
-	char *z1;                                                              \
-	const char *z2;                                                        \
-	int n;                                                                 \
-	UNUSED_PARAMETER(argc);                                                \
-	if (mem_is_bin(&argv[0]) || mem_is_map(&argv[0]) ||                    \
-	    mem_is_array(&argv[0])) {                                          \
-		diag_set(ClientError, ER_INCONSISTENT_TYPES, "string",         \
-			 mem_str(&argv[0]));                                   \
-		context->is_aborted = true;                                    \
-		return;                                                        \
-	}                                                                      \
-	z2 = mem_as_str0(&argv[0]);                                            \
-	n = mem_len_unsafe(&argv[0]);                                          \
-	/*                                                                     \
-	 * Verify that the call to _bytes()                                    \
-	 * does not invalidate the _text() pointer.                            \
-	 */                                                                    \
-	assert(z2 == mem_as_str0(&argv[0]));                                   \
-	if (!z2)                                                               \
-		return;                                                        \
-	z1 = contextMalloc(context, ((i64) n) + 1);                            \
-	if (z1 == NULL) {                                                      \
-		context->is_aborted = true;                                    \
-		return;                                                        \
-	}                                                                      \
-	UErrorCode status = U_ZERO_ERROR;                                      \
-	struct coll *coll = context->coll;                                     \
-	const char *locale = NULL;                                             \
-	if (coll != NULL && coll->type == COLL_TYPE_ICU) {                     \
-		locale = ucol_getLocaleByType(coll->collator,                  \
-					      ULOC_VALID_LOCALE, &status);     \
-	}                                                                      \
-	UCaseMap *case_map = ucasemap_open(locale, 0, &status);                \
-	assert(case_map != NULL);                                              \
-	int len = ucasemap_utf8To##case_type(case_map, z1, n, z2, n, &status); \
-	if (len > n) {                                                         \
-		status = U_ZERO_ERROR;                                         \
-		sql_free(z1);                                              \
-		z1 = contextMalloc(context, ((i64) len) + 1);                  \
-		if (z1 == NULL) {                                              \
-			context->is_aborted = true;                            \
-			return;                                                \
-		}                                                              \
-		ucasemap_utf8To##case_type(case_map, z1, len, z2, n, &status); \
-	}                                                                      \
-	ucasemap_close(case_map);                                              \
-	sql_result_text(context, z1, len, sql_free);                   \
-}                                                                              \
-
-ICU_CASE_CONVERT(Lower);
-ICU_CASE_CONVERT(Upper);
-
-
 /*
  * Some functions like COALESCE() and IFNULL() and UNLIKELY() are implemented
  * as VDBE code so that unused argument values do not have to be computed.
@@ -1989,7 +1981,7 @@ static struct sql_func_definition definitions[] = {
 	 FIELD_TYPE_BOOLEAN, sql_builtin_stub, NULL},
 	{"LIKELY", 1, {FIELD_TYPE_ANY}, FIELD_TYPE_BOOLEAN, sql_builtin_stub,
 	 NULL},
-	{"LOWER", 1, {FIELD_TYPE_STRING}, FIELD_TYPE_STRING, LowerICUFunc,
+	{"LOWER", 1, {FIELD_TYPE_STRING}, FIELD_TYPE_STRING, func_lower_upper,
 	 NULL},
 
 	{"MAX", 1, {FIELD_TYPE_INTEGER}, FIELD_TYPE_INTEGER, step_minmax, NULL},
@@ -2064,7 +2056,7 @@ static struct sql_func_definition definitions[] = {
 	 NULL},
 	{"UNLIKELY", 1, {FIELD_TYPE_ANY}, FIELD_TYPE_BOOLEAN, sql_builtin_stub,
 	 NULL},
-	{"UPPER", 1, {FIELD_TYPE_STRING}, FIELD_TYPE_STRING, UpperICUFunc,
+	{"UPPER", 1, {FIELD_TYPE_STRING}, FIELD_TYPE_STRING, func_lower_upper,
 	 NULL},
 	{"UUID", 0, {}, FIELD_TYPE_UUID, sql_func_uuid, NULL},
 	{"UUID", 1, {FIELD_TYPE_INTEGER}, FIELD_TYPE_UUID, sql_func_uuid, NULL},
-- 
2.25.1


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [Tarantool-patches] [PATCH v1 4/8] sql: refactor NULLIF() function
  2021-11-11 10:45 [Tarantool-patches] [PATCH v1 0/8] Rework standard function Mergen Imeev via Tarantool-patches
                   ` (2 preceding siblings ...)
  2021-11-11 10:45 ` [Tarantool-patches] [PATCH v1 3/8] sql: refactor UPPER() and LOWER() functions Mergen Imeev via Tarantool-patches
@ 2021-11-11 10:45 ` Mergen Imeev via Tarantool-patches
  2021-11-11 10:45 ` [Tarantool-patches] [PATCH v1 5/8] sql: rework TRIM() function Mergen Imeev via Tarantool-patches
                   ` (4 subsequent siblings)
  8 siblings, 0 replies; 15+ messages in thread
From: Mergen Imeev via Tarantool-patches @ 2021-11-11 10:45 UTC (permalink / raw)
  To: kyukhin; +Cc: tarantool-patches

Part of #4145
---
 src/box/sql/func.c | 28 +++++++++++++---------------
 1 file changed, 13 insertions(+), 15 deletions(-)

diff --git a/src/box/sql/func.c b/src/box/sql/func.c
index 88830fd78..7d54a39cd 100644
--- a/src/box/sql/func.c
+++ b/src/box/sql/func.c
@@ -331,6 +331,18 @@ func_lower_upper(struct sql_context *ctx, int argc, struct Mem *argv)
 	mem_set_str_allocated(ctx->pOut, res, new_len);
 }
 
+/** Implementation of the NULLIF() function. */
+static void
+func_nullif(struct sql_context *ctx, int argc, struct Mem *argv)
+{
+	assert(argc == 2);
+	(void)argc;
+	if (mem_cmp_scalar(&argv[0], &argv[1], ctx->coll) == 0)
+		return;
+	if (mem_copy(ctx->pOut, &argv[0]) != 0)
+		ctx->is_aborted = true;
+}
+
 static const unsigned char *
 mem_as_ustr(struct Mem *mem)
 {
@@ -1193,20 +1205,6 @@ likeFunc(sql_context *context, int argc, struct Mem *argv)
 	sql_result_bool(context, res == MATCH);
 }
 
-/*
- * Implementation of the NULLIF(x,y) function.  The result is the first
- * argument if the arguments are different.  The result is NULL if the
- * arguments are equal to each other.
- */
-static void
-nullifFunc(struct sql_context *context, int argc, struct Mem *argv)
-{
-	(void)argc;
-	struct coll *pColl = context->coll;
-	if (mem_cmp_scalar(&argv[0], &argv[1], pColl) != 0)
-		sql_result_value(context, &argv[0]);
-}
-
 /**
  * Implementation of the version() function.  The result is the
  * version of the Tarantool that is running.
@@ -2003,7 +2001,7 @@ static struct sql_func_definition definitions[] = {
 	{"MIN", 1, {FIELD_TYPE_SCALAR}, FIELD_TYPE_SCALAR, step_minmax, NULL},
 
 	{"NULLIF", 2, {FIELD_TYPE_ANY, FIELD_TYPE_ANY}, FIELD_TYPE_SCALAR,
-	 nullifFunc, NULL},
+	 func_nullif, NULL},
 	{"POSITION", 2, {FIELD_TYPE_STRING, FIELD_TYPE_STRING},
 	 FIELD_TYPE_INTEGER, position_func, NULL},
 	{"PRINTF", -1, {FIELD_TYPE_ANY}, FIELD_TYPE_STRING, printfFunc, 
-- 
2.25.1


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [Tarantool-patches] [PATCH v1 5/8] sql: rework TRIM() function
  2021-11-11 10:45 [Tarantool-patches] [PATCH v1 0/8] Rework standard function Mergen Imeev via Tarantool-patches
                   ` (3 preceding siblings ...)
  2021-11-11 10:45 ` [Tarantool-patches] [PATCH v1 4/8] sql: refactor NULLIF() function Mergen Imeev via Tarantool-patches
@ 2021-11-11 10:45 ` Mergen Imeev via Tarantool-patches
  2021-11-11 10:45 ` [Tarantool-patches] [PATCH v1 6/8] sql: rework POSITION() function Mergen Imeev via Tarantool-patches
                   ` (3 subsequent siblings)
  8 siblings, 0 replies; 15+ messages in thread
From: Mergen Imeev via Tarantool-patches @ 2021-11-11 10:45 UTC (permalink / raw)
  To: kyukhin; +Cc: tarantool-patches

This patch refactoring TRIM() and fixes an issue with incorrect trimming
of some VARBINARY values. Also, TRIM() now use ICU functions instead of
self-created.

Part of #4415
---
 src/box/sql/func.c            | 361 ++++++++++++++++------------------
 test/sql-tap/badutf1.test.lua |  41 ++--
 2 files changed, 198 insertions(+), 204 deletions(-)

diff --git a/src/box/sql/func.c b/src/box/sql/func.c
index 7d54a39cd..ba6b9246d 100644
--- a/src/box/sql/func.c
+++ b/src/box/sql/func.c
@@ -343,6 +343,172 @@ func_nullif(struct sql_context *ctx, int argc, struct Mem *argv)
 		ctx->is_aborted = true;
 }
 
+/** Implementation of the TRIM() function. */
+static inline int
+trim_bin_end(const char *str, int end, const char *octets, int octets_size,
+	     int flags)
+{
+	if ((flags & TRIM_TRAILING) == 0)
+		return end;
+	while (end > 0) {
+		bool is_trimmed = false;
+		char c = str[end - 1];
+		for (int i = 0; i < octets_size && !is_trimmed; ++i)
+			is_trimmed = c == octets[i];
+		if (!is_trimmed)
+			break;
+		--end;
+	}
+	return end;
+}
+
+static inline int
+trim_bin_start(const char *str, int end, const char *octets, int octets_size,
+	       int flags)
+{
+	if ((flags & TRIM_LEADING) == 0)
+		return 0;
+	int start = 0;
+	while (start < end) {
+		bool is_trimmed = false;
+		char c = str[start];
+		for (int i = 0; i < octets_size && !is_trimmed; ++i)
+			is_trimmed = c == octets[i];
+		if (!is_trimmed)
+			break;
+		++start;
+	}
+	return start;
+}
+
+static void
+func_trim_bin(struct sql_context *ctx, int argc, struct Mem *argv)
+{
+	if (mem_is_null(&argv[0]) || (argc == 3 && mem_is_null(&argv[2])))
+		return;
+	assert(argc == 2 || (argc == 3 && mem_is_bin(&argv[2])));
+	assert(mem_is_bin(&argv[0]) && mem_is_uint(&argv[1]));
+	const char *str = argv[0].z;
+	int size = argv[0].n;
+	const char *octets;
+	int octets_size;
+	if (argc == 3) {
+		octets = argv[2].z;
+		octets_size = argv[2].n;
+	} else {
+		octets = "\0";
+		octets_size = 1;
+	}
+
+	int flags = argv[1].u.u;
+	int end = trim_bin_end(str, size, octets, octets_size, flags);
+	int start = trim_bin_start(str, end, octets, octets_size, flags);
+
+	if (start >= end)
+		return mem_set_bin_static(ctx->pOut, "", 0);
+	if (mem_copy_bin(ctx->pOut, &str[start], end - start) != 0)
+		ctx->is_aborted = true;
+}
+
+static inline int
+trim_str_end(const char *str, int end, const char *chars, uint8_t *chars_len,
+	     int chars_count, int flags)
+{
+	if ((flags & TRIM_TRAILING) == 0)
+		return end;
+	while (end > 0) {
+		bool is_trimmed = false;
+		const char *c = chars;
+		int len;
+		for (int i = 0; i < chars_count && !is_trimmed; ++i) {
+			len = chars_len[i];
+			const char *s = str + end - len;
+			is_trimmed = len <= end && memcmp(c, s, len) == 0;
+			c += len;
+		}
+		if (!is_trimmed)
+			break;
+		assert(len > 0);
+		end -= len;
+	}
+	return end;
+}
+
+static inline int
+trim_str_start(const char *str, int end, const char *chars, uint8_t *chars_len,
+	       int chars_count, int flags)
+{
+	if ((flags & TRIM_LEADING) == 0)
+		return 0;
+	int start = 0;
+	while (start < end) {
+		bool is_trimmed = false;
+		const char *c = chars;
+		int len;
+		for (int i = 0; i < chars_count && !is_trimmed; ++i) {
+			len = chars_len[i];
+			const char *s = str + start;
+			is_trimmed = start + len <= end &&
+				     memcmp(c, s, len) == 0;
+			c += len;
+		}
+		if (!is_trimmed)
+			break;
+		assert(len > 0);
+		start += len;
+	}
+	return start;
+}
+
+static void
+func_trim_str(struct sql_context *ctx, int argc, struct Mem *argv)
+{
+	if (mem_is_null(&argv[0]) || (argc == 3 && mem_is_null(&argv[2])))
+		return;
+	assert(argc == 2 || (argc == 3 && mem_is_str(&argv[2])));
+	assert(mem_is_str(&argv[0]) && mem_is_uint(&argv[1]));
+	const char *str = argv[0].z;
+	int size = argv[0].n;
+	const char *chars;
+	int chars_size;
+	if (argc == 3) {
+		chars = argv[2].z;
+		chars_size = argv[2].n;
+	} else {
+		chars = " ";
+		chars_size = 1;
+	}
+
+	struct region *region = &fiber()->gc;
+	size_t svp = region_used(region);
+	uint8_t *chars_len = region_alloc(region, chars_size);
+	if (chars_len == NULL) {
+		ctx->is_aborted = true;
+		diag_set(OutOfMemory, chars_size, "region_alloc", "chars_len");
+		return;
+	}
+	int chars_count = 0;
+
+	int offset = 0;
+	while (offset < chars_size) {
+		UChar32 c;
+		int prev = offset;
+		U8_NEXT((uint8_t *)chars, offset, chars_size, c);
+		chars_len[chars_count++] = offset - prev;
+	}
+
+	uint64_t flags = argv[1].u.u;
+	int end = trim_str_end(str, size, chars, chars_len, chars_count, flags);
+	int start = trim_str_start(str, end, chars, chars_len, chars_count,
+				   flags);
+	region_truncate(region, svp);
+
+	if (start >= end)
+		return mem_set_str0_static(ctx->pOut, "");
+	if (mem_copy_str(ctx->pOut, &str[start], end - start) != 0)
+		ctx->is_aborted = true;
+}
+
 static const unsigned char *
 mem_as_ustr(struct Mem *mem)
 {
@@ -1527,193 +1693,6 @@ replaceFunc(struct sql_context *context, int argc, struct Mem *argv)
 		mem_set_bin_dynamic(context->pOut, (char *)zOut, j);
 }
 
-/**
- * Remove characters included in @a trim_set from @a input_str
- * until encounter a character that doesn't belong to @a trim_set.
- * Remove from the side specified by @a flags.
- * @param context SQL context.
- * @param flags Trim specification: left, right or both.
- * @param trim_set The set of characters for trimming.
- * @param char_len Lengths of each UTF-8 character in @a trim_set.
- * @param char_cnt A number of UTF-8 characters in @a trim_set.
- * @param input_str Input string for trimming.
- * @param input_str_sz Input string size in bytes.
- */
-static void
-trim_procedure(struct sql_context *context, enum trim_side_mask flags,
-	       const unsigned char *trim_set, const uint8_t *char_len,
-	       int char_cnt, const unsigned char *input_str, int input_str_sz)
-{
-	if (char_cnt == 0)
-		goto finish;
-	int i, len;
-	const unsigned char *z;
-	if ((flags & TRIM_LEADING) != 0) {
-		while (input_str_sz > 0) {
-			z = trim_set;
-			for (i = 0; i < char_cnt; ++i, z += len) {
-				len = char_len[i];
-				if (len <= input_str_sz
-				    && memcmp(input_str, z, len) == 0)
-					break;
-			}
-			if (i >= char_cnt)
-				break;
-			input_str += len;
-			input_str_sz -= len;
-		}
-	}
-	if ((flags & TRIM_TRAILING) != 0) {
-		while (input_str_sz > 0) {
-			z = trim_set;
-			for (i = 0; i < char_cnt; ++i, z += len) {
-				len = char_len[i];
-				if (len <= input_str_sz
-				    && memcmp(&input_str[input_str_sz - len],
-					      z, len) == 0)
-					break;
-			}
-			if (i >= char_cnt)
-				break;
-			input_str_sz -= len;
-		}
-	}
-finish:
-	if (context->func->def->returns == FIELD_TYPE_STRING)
-		mem_copy_str(context->pOut, (char *)input_str, input_str_sz);
-	else
-		mem_copy_bin(context->pOut, (char *)input_str, input_str_sz);
-}
-
-/**
- * Prepare arguments for trimming procedure. Allocate memory for
- * @a char_len (array of lengths each character in @a trim_set)
- * and fill it.
- *
- * @param context SQL context.
- * @param trim_set The set of characters for trimming.
- * @param[out] char_len Lengths of each character in @ trim_set.
- * @retval >=0 A number of UTF-8 characters in @a trim_set.
- * @retval -1 Memory allocation error.
- */
-static int
-trim_prepare_char_len(struct sql_context *context,
-		      const unsigned char *trim_set, int trim_set_sz,
-		      uint8_t **char_len)
-{
-	/*
-	 * Count the number of UTF-8 characters passing through
-	 * the entire char set, but not up to the '\0' or X'00'
-	 * character. This allows to handle trimming set
-	 * containing such characters.
-	 */
-	int char_cnt = sql_utf8_char_count(trim_set, trim_set_sz);
-	if (char_cnt == 0) {
-		*char_len = NULL;
-		return 0;
-	}
-
-	if ((*char_len = (uint8_t *)contextMalloc(context, char_cnt)) == NULL)
-		return -1;
-
-	int i = 0, j = 0;
-	while(j < char_cnt) {
-		int old_i = i;
-		SQL_UTF8_FWD_1(trim_set, i, trim_set_sz);
-		(*char_len)[j++] = i - old_i;
-	}
-
-	return char_cnt;
-}
-
-/**
- * Normalize args from @a argv input array when it has two args.
- *
- * Case: TRIM(<str>)
- * Call trimming procedure with TRIM_BOTH as the flags and " " as
- * the trimming set.
- *
- * Case: TRIM(LEADING/TRAILING/BOTH FROM <str>)
- * If user has specified side keyword only, then call trimming
- * procedure with the specified side and " " as the trimming set.
- */
-static void
-trim_func_two_args(struct sql_context *context, sql_value *arg1,
-		   sql_value *arg2)
-{
-	const unsigned char *trim_set;
-	if (mem_is_bin(arg1))
-		trim_set = (const unsigned char *)"\0";
-	else
-		trim_set = (const unsigned char *)" ";
-	const unsigned char *input_str;
-	if ((input_str = mem_as_ustr(arg1)) == NULL)
-		return;
-
-	int input_str_sz = mem_len_unsafe(arg1);
-	assert(arg2->type == MEM_TYPE_UINT);
-	uint8_t len_one = 1;
-	trim_procedure(context, arg2->u.u, trim_set,
-		       &len_one, 1, input_str, input_str_sz);
-}
-
-/**
- * Normalize args from @a argv input array when it has three args.
- *
- * Case: TRIM(<character_set> FROM <str>)
- * If user has specified <character_set> only, call trimming procedure with
- * TRIM_BOTH as the flags and that trimming set.
- *
- * Case: TRIM(LEADING/TRAILING/BOTH <character_set> FROM <str>)
- * If user has specified side keyword and <character_set>, then
- * call trimming procedure with that args.
- */
-static void
-trim_func_three_args(struct sql_context *context, sql_value *arg1,
-		     sql_value *arg2, sql_value *arg3)
-{
-	assert(arg2->type == MEM_TYPE_UINT);
-	const unsigned char *input_str, *trim_set;
-	if ((input_str = mem_as_ustr(arg1)) == NULL ||
-	    (trim_set = mem_as_ustr(arg3)) == NULL)
-		return;
-
-	int trim_set_sz = mem_len_unsafe(arg3);
-	int input_str_sz = mem_len_unsafe(arg1);
-	uint8_t *char_len;
-	int char_cnt = trim_prepare_char_len(context, trim_set, trim_set_sz,
-					     &char_len);
-	if (char_cnt == -1)
-		return;
-	trim_procedure(context, arg2->u.u, trim_set, char_len,
-		       char_cnt, input_str, input_str_sz);
-	sql_free(char_len);
-}
-
-/**
- * Normalize args from @a argv input array when it has one,
- * two or three args.
- *
- * This is a dispatcher function that calls corresponding
- * implementation depending on the number of arguments.
-*/
-static void
-trim_func(struct sql_context *context, int argc, struct Mem *argv)
-{
-	switch (argc) {
-	case 2:
-		trim_func_two_args(context, &argv[0], &argv[1]);
-		break;
-	case 3:
-		trim_func_three_args(context, &argv[0], &argv[1], &argv[2]);
-		break;
-	default:
-		diag_set(ClientError, ER_FUNC_WRONG_ARG_COUNT, "TRIM",
-			"2 or 3", argc);
-		context->is_aborted = true;
-	}
-}
-
 /*
  * Compute the soundex encoding of a word.
  *
@@ -2040,14 +2019,14 @@ static struct sql_func_definition definitions[] = {
 	 fin_total},
 
 	{"TRIM", 2, {FIELD_TYPE_STRING, FIELD_TYPE_INTEGER},
-	 FIELD_TYPE_STRING, trim_func, NULL},
+	 FIELD_TYPE_STRING, func_trim_str, NULL},
 	{"TRIM", 3, {FIELD_TYPE_STRING, FIELD_TYPE_INTEGER, FIELD_TYPE_STRING},
-	 FIELD_TYPE_STRING, trim_func, NULL},
+	 FIELD_TYPE_STRING, func_trim_str, NULL},
 	{"TRIM", 2, {FIELD_TYPE_VARBINARY, FIELD_TYPE_INTEGER},
-	 FIELD_TYPE_VARBINARY, trim_func, NULL},
+	 FIELD_TYPE_VARBINARY, func_trim_bin, NULL},
 	{"TRIM", 3,
 	 {FIELD_TYPE_VARBINARY, FIELD_TYPE_INTEGER, FIELD_TYPE_VARBINARY},
-	 FIELD_TYPE_VARBINARY, trim_func, NULL},
+	 FIELD_TYPE_VARBINARY, func_trim_bin, NULL},
 
 	{"TYPEOF", 1, {FIELD_TYPE_ANY}, FIELD_TYPE_STRING, typeofFunc, NULL},
 	{"UNICODE", 1, {FIELD_TYPE_STRING}, FIELD_TYPE_INTEGER, unicodeFunc,
diff --git a/test/sql-tap/badutf1.test.lua b/test/sql-tap/badutf1.test.lua
index ce8354840..d1e17ca3e 100755
--- a/test/sql-tap/badutf1.test.lua
+++ b/test/sql-tap/badutf1.test.lua
@@ -1,6 +1,6 @@
 #!/usr/bin/env tarantool
 local test = require("sqltester")
-test:plan(19)
+test:plan(20)
 
 --!./tcltestrunner.lua
 -- 2007 May 15
@@ -296,47 +296,62 @@ test:do_test(
 test:do_test(
     "badutf-4.4",
     function()
-        return test:execsql2([[SELECT hex(CAST(TRIM(x'ff80' FROM ]]..
-                             [[x'808080f0808080ff') AS VARBINARY)) AS x]])
+        return test:execsql2([[
+            SELECT hex(TRIM(x'ff80' FROM x'808080f0808080ff')) AS x;
+        ]])
     end, {
         -- <badutf-4.4>
-        "X", "808080F0808080FF"
+        "X", "F0"
         -- </badutf-4.4>
     })
 
 test:do_test(
     "badutf-4.5",
     function()
-        return test:execsql2([[SELECT hex(CAST(TRIM(x'ff80' FROM ]]..
-                             [[x'ff8080f0808080ff') AS VARBINARY)) AS x]])
+        return test:execsql2([[
+            SELECT hex(TRIM(x'ff80' FROM x'ff8080f0808080ff')) AS x;
+        ]])
     end, {
         -- <badutf-4.5>
-        "X", "80F0808080FF"
+        "X", "F0"
         -- </badutf-4.5>
     })
 
 test:do_test(
     "badutf-4.6",
     function()
-        return test:execsql2([[SELECT hex(CAST(TRIM(x'ff80' FROM ]]..
-                             [[x'ff80f0808080ff') AS VARBINARY)) AS x]])
+        return test:execsql2([[
+            SELECT hex(TRIM(x'ff80' FROM x'ff80f0808080ff')) AS x;
+        ]])
     end, {
         -- <badutf-4.6>
-        "X", "F0808080FF"
+        "X", "F0"
         -- </badutf-4.6>
     })
 
 test:do_test(
     "badutf-4.7",
     function()
-        return test:execsql2([[SELECT hex(CAST(TRIM(x'ff8080' FROM ]]..
-                             [[x'ff80f0808080ff') AS VARBINARY)) AS x]])
+        return test:execsql2([[
+            SELECT hex(TRIM(x'ff8080' FROM x'ff80f0808080ff')) AS x;
+        ]])
     end, {
         -- <badutf-4.7>
-        "X", "FF80F0808080FF"
+        "X", "F0"
         -- </badutf-4.7>
     })
 
+-- gh-4145: Make sure that TRIM() properly work with VARBINARY.
+test:do_execsql_test(
+    "badutf-5",
+    [[
+        SELECT HEX(TRIM(x'ff1234' from x'1234125678123412'));
+    ]],
+    {
+        '5678'
+    }
+)
+
 --db2("close")
 
 
-- 
2.25.1


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [Tarantool-patches] [PATCH v1 6/8] sql: rework POSITION() function
  2021-11-11 10:45 [Tarantool-patches] [PATCH v1 0/8] Rework standard function Mergen Imeev via Tarantool-patches
                   ` (4 preceding siblings ...)
  2021-11-11 10:45 ` [Tarantool-patches] [PATCH v1 5/8] sql: rework TRIM() function Mergen Imeev via Tarantool-patches
@ 2021-11-11 10:45 ` Mergen Imeev via Tarantool-patches
  2021-11-11 10:45 ` [Tarantool-patches] [PATCH v1 7/8] sql: rework SUBSTR() function Mergen Imeev via Tarantool-patches
                   ` (2 subsequent siblings)
  8 siblings, 0 replies; 15+ messages in thread
From: Mergen Imeev via Tarantool-patches @ 2021-11-11 10:45 UTC (permalink / raw)
  To: kyukhin; +Cc: tarantool-patches

This patch is a refactoring of POSITION(). In addition, VARBINARY
arguments can now be used in this function. In addition, POSITION() now
uses ICU functions instead of self-created.

Part of #4145
---
 src/box/sql/func.c             | 203 +++++++++++----------------------
 test/sql-tap/position.test.lua |  80 +++++++------
 2 files changed, 112 insertions(+), 171 deletions(-)

diff --git a/src/box/sql/func.c b/src/box/sql/func.c
index ba6b9246d..7914d2ec7 100644
--- a/src/box/sql/func.c
+++ b/src/box/sql/func.c
@@ -509,6 +509,70 @@ func_trim_str(struct sql_context *ctx, int argc, struct Mem *argv)
 		ctx->is_aborted = true;
 }
 
+/** Implementation of the POSITION() function. */
+static void
+func_position_octets(struct sql_context *ctx, int argc, struct Mem *argv)
+{
+	assert(argc == 2);
+	(void)argc;
+	if (mem_is_any_null(&argv[0], &argv[1]))
+		return;
+	assert(mem_is_bytes(&argv[0]) && mem_is_bytes(&argv[1]));
+
+	const char *key = argv[0].z;
+	const char *str = argv[1].z;
+	int key_size = argv[0].n;
+	int str_size = argv[1].n;
+	if (key_size <= 0)
+		return mem_set_uint(ctx->pOut, 1);
+	const char *pos = memmem(str, str_size, key, key_size);
+	return mem_set_uint(ctx->pOut, pos == NULL ? 0 : pos - str + 1);
+}
+
+static void
+func_position_characters(struct sql_context *ctx, int argc, struct Mem *argv)
+{
+	assert(argc == 2);
+	(void)argc;
+	if (mem_is_any_null(&argv[0], &argv[1]))
+		return;
+	assert(mem_is_str(&argv[0]) && mem_is_str(&argv[1]));
+
+	const char *key = argv[0].z;
+	const char *str = argv[1].z;
+	int key_size = argv[0].n;
+	int str_size = argv[1].n;
+	if (key_size <= 0)
+		return mem_set_uint(ctx->pOut, 1);
+
+	int key_end = 0;
+	int str_end = 0;
+	while (key_end < key_size && str_end < str_size) {
+		UChar32 c;
+		U8_NEXT((uint8_t *)key, key_end, key_size, c);
+		U8_NEXT((uint8_t *)str, str_end, str_size, c);
+	}
+	if (key_end < key_size)
+		return mem_set_uint(ctx->pOut, 0);
+
+	struct coll *coll = ctx->coll;
+	if (coll->cmp(key, key_size, str, str_end, coll) == 0)
+		return mem_set_uint(ctx->pOut, 1);
+
+	int i = 2;
+	int str_pos = 0;
+	while (str_end < str_size) {
+		UChar32 c;
+		U8_NEXT((uint8_t *)str, str_pos, str_size, c);
+		U8_NEXT((uint8_t *)str, str_end, str_size, c);
+		const char *s = str + str_pos;
+		if (coll->cmp(key, key_size, s, str_end - str_pos, coll) == 0)
+			return mem_set_uint(ctx->pOut, i);
+		++i;
+	}
+	return mem_set_uint(ctx->pOut, 0);
+}
+
 static const unsigned char *
 mem_as_ustr(struct Mem *mem)
 {
@@ -672,141 +736,6 @@ lengthFunc(struct sql_context *context, int argc, struct Mem *argv)
 	}
 }
 
-/**
- * Implementation of the position() function.
- *
- * position(needle, haystack) finds the first occurrence of needle
- * in haystack and returns the number of previous characters
- * plus 1, or 0 if needle does not occur within haystack.
- *
- * If both haystack and needle are BLOBs, then the result is one
- * more than the number of bytes in haystack prior to the first
- * occurrence of needle, or 0 if needle never occurs in haystack.
- */
-static void
-position_func(struct sql_context *context, int argc, struct Mem *argv)
-{
-	UNUSED_PARAMETER(argc);
-	struct Mem *needle = &argv[0];
-	struct Mem *haystack = &argv[1];
-	enum mp_type needle_type = sql_value_type(needle);
-	enum mp_type haystack_type = sql_value_type(haystack);
-
-	if (haystack_type == MP_NIL || needle_type == MP_NIL)
-		return;
-	/*
-	 * Position function can be called only with string
-	 * or blob params.
-	 */
-	struct Mem *inconsistent_type_arg = NULL;
-	if (needle_type != MP_STR && needle_type != MP_BIN)
-		inconsistent_type_arg = needle;
-	if (haystack_type != MP_STR && haystack_type != MP_BIN)
-		inconsistent_type_arg = haystack;
-	if (inconsistent_type_arg != NULL) {
-		diag_set(ClientError, ER_INCONSISTENT_TYPES,
-			 "string or varbinary", mem_str(inconsistent_type_arg));
-		context->is_aborted = true;
-		return;
-	}
-	/*
-	 * Both params of Position function must be of the same
-	 * type.
-	 */
-	if (haystack_type != needle_type) {
-		diag_set(ClientError, ER_INCONSISTENT_TYPES,
-			 mem_type_to_str(needle), mem_str(haystack));
-		context->is_aborted = true;
-		return;
-	}
-
-	int n_needle_bytes = mem_len_unsafe(needle);
-	int n_haystack_bytes = mem_len_unsafe(haystack);
-	int position = 1;
-	if (n_needle_bytes > 0) {
-		const unsigned char *haystack_str;
-		const unsigned char *needle_str;
-		if (haystack_type == MP_BIN) {
-			needle_str = mem_as_bin(needle);
-			haystack_str = mem_as_bin(haystack);
-			assert(needle_str != NULL);
-			assert(haystack_str != NULL || n_haystack_bytes == 0);
-			/*
-			 * Naive implementation of substring
-			 * searching: matching time O(n * m).
-			 * Can be improved.
-			 */
-			while (n_needle_bytes <= n_haystack_bytes &&
-			       memcmp(haystack_str, needle_str, n_needle_bytes) != 0) {
-				position++;
-				n_haystack_bytes--;
-				haystack_str++;
-			}
-			if (n_needle_bytes > n_haystack_bytes)
-				position = 0;
-		} else {
-			/*
-			 * Code below handles not only simple
-			 * cases like position('a', 'bca'), but
-			 * also more complex ones:
-			 * position('a', 'bcá' COLLATE "unicode_ci")
-			 * To do so, we need to use comparison
-			 * window, which has constant character
-			 * size, but variable byte size.
-			 * Character size is equal to
-			 * needle char size.
-			 */
-			haystack_str = mem_as_ustr(haystack);
-			needle_str = mem_as_ustr(needle);
-
-			int n_needle_chars =
-				sql_utf8_char_count(needle_str, n_needle_bytes);
-			int n_haystack_chars =
-				sql_utf8_char_count(haystack_str,
-						    n_haystack_bytes);
-
-			if (n_haystack_chars < n_needle_chars) {
-				position = 0;
-				goto finish;
-			}
-			/*
-			 * Comparison window is determined by
-			 * beg_offset and end_offset. beg_offset
-			 * is offset in bytes from haystack
-			 * beginning to window beginning.
-			 * end_offset is offset in bytes from
-			 * haystack beginning to window end.
-			 */
-			int end_offset = 0;
-			for (int c = 0; c < n_needle_chars; c++) {
-				SQL_UTF8_FWD_1(haystack_str, end_offset,
-					       n_haystack_bytes);
-			}
-			int beg_offset = 0;
-			struct coll *coll = context->coll;
-			int c;
-			for (c = 0; c + n_needle_chars <= n_haystack_chars; c++) {
-				if (coll->cmp((const char *) haystack_str + beg_offset,
-					      end_offset - beg_offset,
-					      (const char *) needle_str,
-					      n_needle_bytes, coll) == 0)
-					goto finish;
-				position++;
-				/* Update offsets. */
-				SQL_UTF8_FWD_1(haystack_str, beg_offset,
-					       n_haystack_bytes);
-				SQL_UTF8_FWD_1(haystack_str, end_offset,
-					       n_haystack_bytes);
-			}
-			/* Needle was not found in the haystack. */
-			position = 0;
-		}
-	}
-finish:
-	assert(position >= 0);
-	sql_result_uint(context, position);
-}
-
 /*
  * Implementation of the printf() function.
  */
@@ -1982,7 +1911,9 @@ static struct sql_func_definition definitions[] = {
 	{"NULLIF", 2, {FIELD_TYPE_ANY, FIELD_TYPE_ANY}, FIELD_TYPE_SCALAR,
 	 func_nullif, NULL},
 	{"POSITION", 2, {FIELD_TYPE_STRING, FIELD_TYPE_STRING},
-	 FIELD_TYPE_INTEGER, position_func, NULL},
+	 FIELD_TYPE_INTEGER, func_position_characters, NULL},
+	{"POSITION", 2, {FIELD_TYPE_VARBINARY, FIELD_TYPE_VARBINARY},
+	 FIELD_TYPE_INTEGER, func_position_octets, NULL},
 	{"PRINTF", -1, {FIELD_TYPE_ANY}, FIELD_TYPE_STRING, printfFunc, 
 	 NULL},
 	{"QUOTE", 1, {FIELD_TYPE_ANY}, FIELD_TYPE_STRING, quoteFunc, NULL},
diff --git a/test/sql-tap/position.test.lua b/test/sql-tap/position.test.lua
index 6a96ed9bc..e49f4665a 100755
--- a/test/sql-tap/position.test.lua
+++ b/test/sql-tap/position.test.lua
@@ -1,6 +1,6 @@
 #!/usr/bin/env tarantool
 local test = require("sqltester")
-test:plan(80)
+test:plan(81)
 
 test:do_test(
     "position-1.1",
@@ -305,130 +305,130 @@ test:do_test(
 test:do_test(
     "position-1.31",
     function()
-        return test:catchsql "SELECT position(x'01', x'0102030405');"
+        return test:execsql "SELECT position(x'01', x'0102030405');"
     end, {
         -- <position-1.31>
-        1, "Failed to execute SQL statement: wrong arguments for function POSITION()"
+        1
         -- </position-1.31>
     })
 
 test:do_test(
     "position-1.32",
     function()
-        return test:catchsql "SELECT position(x'02', x'0102030405');"
+        return test:execsql "SELECT position(x'02', x'0102030405');"
     end, {
         -- <position-1.32>
-        1, "Failed to execute SQL statement: wrong arguments for function POSITION()"
+        2
         -- </position-1.32>
     })
 
 test:do_test(
     "position-1.33",
     function()
-        return test:catchsql "SELECT position(x'03', x'0102030405');"
+        return test:execsql "SELECT position(x'03', x'0102030405');"
     end, {
         -- <position-1.33>
-        1, "Failed to execute SQL statement: wrong arguments for function POSITION()"
+        3
         -- </position-1.33>
     })
 
 test:do_test(
     "position-1.34",
     function()
-        return test:catchsql "SELECT position(x'04', x'0102030405');"
+        return test:execsql "SELECT position(x'04', x'0102030405');"
     end, {
         -- <position-1.34>
-        1, "Failed to execute SQL statement: wrong arguments for function POSITION()"
+        4
         -- </position-1.34>
     })
 
 test:do_test(
     "position-1.35",
     function()
-        return test:catchsql "SELECT position(x'05', x'0102030405');"
+        return test:execsql "SELECT position(x'05', x'0102030405');"
     end, {
         -- <position-1.35>
-        1, "Failed to execute SQL statement: wrong arguments for function POSITION()"
+        5
         -- </position-1.35>
     })
 
 test:do_test(
     "position-1.36",
     function()
-        return test:catchsql "SELECT position(x'06', x'0102030405');"
+        return test:execsql "SELECT position(x'06', x'0102030405');"
     end, {
         -- <position-1.36>
-        1, "Failed to execute SQL statement: wrong arguments for function POSITION()"
+        0
         -- </position-1.36>
     })
 
 test:do_test(
     "position-1.37",
     function()
-        return test:catchsql "SELECT position(x'0102030405', x'0102030405');"
+        return test:execsql "SELECT position(x'0102030405', x'0102030405');"
     end, {
         -- <position-1.37>
-        1, "Failed to execute SQL statement: wrong arguments for function POSITION()"
+        1
         -- </position-1.37>
     })
 
 test:do_test(
     "position-1.38",
     function()
-        return test:catchsql "SELECT position(x'02030405', x'0102030405');"
+        return test:execsql "SELECT position(x'02030405', x'0102030405');"
     end, {
         -- <position-1.38>
-        1, "Failed to execute SQL statement: wrong arguments for function POSITION()"
+        2
         -- </position-1.38>
     })
 
 test:do_test(
     "position-1.39",
     function()
-        return test:catchsql "SELECT position(x'030405', x'0102030405');"
+        return test:execsql "SELECT position(x'030405', x'0102030405');"
     end, {
         -- <position-1.39>
-        1, "Failed to execute SQL statement: wrong arguments for function POSITION()"
+        3
         -- </position-1.39>
     })
 
 test:do_test(
     "position-1.40",
     function()
-        return test:catchsql "SELECT position(x'0405', x'0102030405');"
+        return test:execsql "SELECT position(x'0405', x'0102030405');"
     end, {
         -- <position-1.40>
-        1, "Failed to execute SQL statement: wrong arguments for function POSITION()"
+        4
         -- </position-1.40>
     })
 
 test:do_test(
     "position-1.41",
     function()
-        return test:catchsql "SELECT position(x'0506', x'0102030405');"
+        return test:execsql "SELECT position(x'0506', x'0102030405');"
     end, {
         -- <position-1.41>
-        1, "Failed to execute SQL statement: wrong arguments for function POSITION()"
+        0
         -- </position-1.41>
     })
 
 test:do_test(
     "position-1.42",
     function()
-        return test:catchsql "SELECT position(x'', x'0102030405');"
+        return test:execsql "SELECT position(x'', x'0102030405');"
     end, {
         -- <position-1.42>
-        1, "Failed to execute SQL statement: wrong arguments for function POSITION()"
+        1
         -- </position-1.42>
     })
 
 test:do_test(
     "position-1.43",
     function()
-        return test:catchsql "SELECT position(x'', x'');"
+        return test:execsql "SELECT position(x'', x'');"
     end, {
         -- <position-1.43>
-        1, "Failed to execute SQL statement: wrong arguments for function POSITION()"
+        1
         -- </position-1.43>
     })
 
@@ -571,40 +571,40 @@ test:do_test(
 test:do_test(
     "position-1.56.1",
     function()
-        return test:catchsql "SELECT position(x'79', x'78c3a4e282ac79');"
+        return test:execsql "SELECT position(x'79', x'78c3a4e282ac79');"
     end, {
         -- <position-1.56.1>
-        1, "Failed to execute SQL statement: wrong arguments for function POSITION()"
+        7
         -- </position-1.56.1>
     })
 
 test:do_test(
     "position-1.56.2",
     function()
-        return test:catchsql "SELECT position(x'7a', x'78c3a4e282ac79');"
+        return test:execsql "SELECT position(x'7a', x'78c3a4e282ac79');"
     end, {
         -- <position-1.56.2>
-        1, "Failed to execute SQL statement: wrong arguments for function POSITION()"
+        0
         -- </position-1.56.2>
     })
 
 test:do_test(
     "position-1.56.3",
     function()
-        return test:catchsql "SELECT position(x'78', x'78c3a4e282ac79');"
+        return test:execsql "SELECT position(x'78', x'78c3a4e282ac79');"
     end, {
         -- <position-1.56.3>
-        1, "Failed to execute SQL statement: wrong arguments for function POSITION()"
+        1
         -- </position-1.56.3>
     })
 
 test:do_test(
     "position-1.56.3",
     function()
-        return test:catchsql "SELECT position(x'a4', x'78c3a4e282ac79');"
+        return test:execsql "SELECT position(x'a4', x'78c3a4e282ac79');"
     end, {
         -- <position-1.56.3>
-        1, "Failed to execute SQL statement: wrong arguments for function POSITION()"
+        3
         -- </position-1.56.3>
     })
 
@@ -858,4 +858,14 @@ test:do_catchsql_test(
     }
 )
 
+-- gh-4145: Make sure POSITION() can work with VARBINARY.
+test:do_execsql_test(
+    "position-2",
+    [[
+        SELECT POSITION(x'313233', x'30313231323334353132333435');
+    ]], {
+        4
+    }
+)
+
 test:finish_test()
-- 
2.25.1


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [Tarantool-patches] [PATCH v1 7/8] sql: rework SUBSTR() function
  2021-11-11 10:45 [Tarantool-patches] [PATCH v1 0/8] Rework standard function Mergen Imeev via Tarantool-patches
                   ` (5 preceding siblings ...)
  2021-11-11 10:45 ` [Tarantool-patches] [PATCH v1 6/8] sql: rework POSITION() function Mergen Imeev via Tarantool-patches
@ 2021-11-11 10:45 ` Mergen Imeev via Tarantool-patches
  2021-11-11 10:45 ` [Tarantool-patches] [PATCH v1 8/8] sql: refactor LIKE() function Mergen Imeev via Tarantool-patches
  2021-11-11 10:59 ` [Tarantool-patches] [PATCH v1 0/8] Rework standard function Kirill Yukhin via Tarantool-patches
  8 siblings, 0 replies; 15+ messages in thread
From: Mergen Imeev via Tarantool-patches @ 2021-11-11 10:45 UTC (permalink / raw)
  To: kyukhin; +Cc: tarantool-patches

This patch makes SUBSTR() work according to ANSI rules for SUBSTRING()
function. Also, SUBSTR() can now work correctly with large INTEGER
values. The SUBSTR() syntax has not changed.

Part of #4145

@TarantoolBot document
Title: SUBSTR() function

SUBSTR() now works according to the ANSI rules for SUBSTRING().

Rules for SUBSTR() with 2 arguments:
1) let the first argument be VALUE, and the second argument be START;
2) VALUE should be STRING or VARBINARY, START should be INTEGER;
3) if any of arguments is NULL, NULL is returned;
4) let POS be MAX(START - 1, 0), END be length of the VALUE;
5) if POS >= END, the result is empty string;
6) if POS < END, the result will be substring of VALUE, starting from
   the position POS to the position END.

Rules for SUBSTR() with 3 arguments:
1) let the first argument be VALUE, the second argument be START, and
   the third argument be LENGTH;
2) VALUE should be STRING or VARBINARY, START and LENGTH should be
   INTEGERs;
3) if any of arguments is NULL, NULL is returned;
4) if LENGTH < 0, an error is thrown;
5) let POS be MAX(START - 1, 0), END be START + LENGTH - 1;
6) if POS >= END, the result is empty string;
7) if POS < END, the result will be substring of VALUE, starting from
   the position POS to the position END.
---
 src/box/sql/func.c           | 273 ++++++++++++++++++++---------------
 test/sql-tap/func.test.lua   |  16 +-
 test/sql-tap/func2.test.lua  | 150 +++++++++----------
 test/sql-tap/substr.test.lua | 121 ++++++++++++----
 4 files changed, 339 insertions(+), 221 deletions(-)

diff --git a/src/box/sql/func.c b/src/box/sql/func.c
index 7914d2ec7..7e71a757b 100644
--- a/src/box/sql/func.c
+++ b/src/box/sql/func.c
@@ -573,6 +573,161 @@ func_position_characters(struct sql_context *ctx, int argc, struct Mem *argv)
 	return mem_set_uint(ctx->pOut, 0);
 }
 
+/** Implementation of the SUBSTR() function. */
+int
+substr_normalize(int64_t base_start, bool is_start_neg, uint64_t base_length,
+		 uint64_t *start, uint64_t *length)
+{
+	if (!is_start_neg && base_start > 0) {
+		*start = (uint64_t)base_start - 1;
+		*length = base_length;
+		return 0;
+	}
+	*start = 0;
+	if (base_length == 0) {
+		*length = 0;
+		return 0;
+	}
+	/*
+	 * We are subtracting 1 from base_length instead of subtracting from
+	 * base_start, since base_start can be INT64_MIN. At the same time,
+	 * base_length is not less than 1.
+	 */
+	int64_t a = base_start;
+	int64_t b = (int64_t)(base_length - 1);
+	int64_t res;
+	bool is_neg;
+	/*
+	 * Integer cannot overflow since non-positive value is added to positive
+	 * value.
+	 */
+	if (sql_add_int(a, a != 0, b, false, &res, &is_neg) != 0) {
+		diag_set(ClientError, ER_SQL_EXECUTE, "integer is overflowed");
+		return -1;
+	}
+	*length = is_neg ? 0 : (uint64_t)res;
+	return 0;
+}
+
+static void
+func_substr_octets(struct sql_context *ctx, int argc, struct Mem *argv)
+{
+	assert(argc == 2 || argc == 3);
+	if (mem_is_any_null(&argv[0], &argv[1]))
+		return;
+	assert(mem_is_bytes(&argv[0]) && mem_is_int(&argv[1]));
+
+	bool is_str = mem_is_str(&argv[0]);
+	uint64_t size = argv[0].n;
+
+	if (argc == 2) {
+		uint64_t start = mem_is_uint(&argv[1]) && argv[1].u.u > 1 ?
+				 argv[1].u.u - 1 : 0;
+		if (start >= size) {
+			if (is_str)
+				return mem_set_str0_static(ctx->pOut, "");
+			else
+				return mem_set_bin_static(ctx->pOut, "", 0);
+		}
+		char *s = &argv[0].z[start];
+		uint64_t n = size - start;
+		ctx->is_aborted = is_str ? mem_copy_str(ctx->pOut, s, n) != 0 :
+				  mem_copy_bin(ctx->pOut, s, n) != 0;
+		return;
+	}
+
+	assert(argc == 3);
+	if (mem_is_null(&argv[2]))
+		return;
+	assert(mem_is_int(&argv[2]));
+	if (!mem_is_uint(&argv[2])) {
+		diag_set(ClientError, ER_SQL_EXECUTE, "Length of the result "
+			 "cannot be less than 0");
+		ctx->is_aborted = true;
+		return;
+	}
+	uint64_t start;
+	uint64_t length;
+	if (substr_normalize(argv[1].u.i, !mem_is_uint(&argv[1]), argv[2].u.u,
+			     &start, &length) != 0) {
+		ctx->is_aborted = true;
+		return;
+	}
+	if (start >= size || length == 0) {
+		if (is_str)
+			return mem_set_str0_static(ctx->pOut, "");
+		else
+			return mem_set_bin_static(ctx->pOut, "", 0);
+	}
+	char *str = &argv[0].z[start];
+	uint64_t len = MIN(size - start, length);
+	ctx->is_aborted = is_str ? mem_copy_str(ctx->pOut, str, len) != 0 :
+			  mem_copy_bin(ctx->pOut, str, len) != 0;
+}
+
+static void
+func_substr_characters(struct sql_context *ctx, int argc, struct Mem *argv)
+{
+	assert(argc == 2 || argc == 3);
+	(void)argc;
+	if (mem_is_any_null(&argv[0], &argv[1]))
+		return;
+	assert(mem_is_str(&argv[0]) && mem_is_int(&argv[1]));
+
+	const char *str = argv[0].z;
+	int pos = 0;
+	int end = argv[0].n;
+	if (argc == 2) {
+		uint64_t start = mem_is_uint(&argv[1]) && argv[1].u.u > 1 ?
+				 argv[1].u.u - 1 : 0;
+		for (uint64_t i = 0; i < start && pos < end; ++i) {
+			UChar32 c;
+			U8_NEXT((uint8_t *)str, pos, end, c);
+		}
+		if (pos == end)
+			return mem_set_str_static(ctx->pOut, "", 0);
+		if (mem_copy_str(ctx->pOut, str + pos, end - pos) != 0)
+			ctx->is_aborted = true;
+		return;
+	}
+
+	assert(argc == 3);
+	if (mem_is_null(&argv[2]))
+		return;
+	assert(mem_is_int(&argv[2]));
+	if (!mem_is_uint(&argv[2])) {
+		diag_set(ClientError, ER_SQL_EXECUTE, "Length of the result "
+			 "cannot be less than 0");
+		ctx->is_aborted = true;
+		return;
+	}
+	uint64_t start;
+	uint64_t length;
+	if (substr_normalize(argv[1].u.i, !mem_is_uint(&argv[1]), argv[2].u.u,
+			     &start, &length) != 0) {
+		ctx->is_aborted = true;
+		return;
+	}
+	if (length == 0)
+		return mem_set_str_static(ctx->pOut, "", 0);
+
+	for (uint64_t i = 0; i < start && pos < end; ++i) {
+		UChar32 c;
+		U8_NEXT((uint8_t *)str, pos, end, c);
+	}
+	if (pos == end)
+		return mem_set_str_static(ctx->pOut, "", 0);
+
+	int cur = pos;
+	for (uint64_t i = 0; i < length && cur < end; ++i) {
+		UChar32 c;
+		U8_NEXT((uint8_t *)str, cur, end, c);
+	}
+	assert(cur > pos);
+	if (mem_copy_str(ctx->pOut, str + pos, cur - pos) != 0)
+		ctx->is_aborted = true;
+}
+
 static const unsigned char *
 mem_as_ustr(struct Mem *mem)
 {
@@ -770,116 +925,6 @@ printfFunc(struct sql_context *context, int argc, struct Mem *argv)
 	}
 }
 
-/*
- * Implementation of the substr() function.
- *
- * substr(x,p1,p2)  returns p2 characters of x[] beginning with p1.
- * p1 is 1-indexed.  So substr(x,1,1) returns the first character
- * of x.  If x is text, then we actually count UTF-8 characters.
- * If x is a blob, then we count bytes.
- *
- * If p1 is negative, then we begin abs(p1) from the end of x[].
- *
- * If p2 is negative, return the p2 characters preceding p1.
- */
-static void
-substrFunc(struct sql_context *context, int argc, struct Mem *argv)
-{
-	const unsigned char *z;
-	const unsigned char *z2;
-	int len;
-	int p0type;
-	int64_t p1, p2;
-	int negP2 = 0;
-
-	if (argc != 2 && argc != 3) {
-		diag_set(ClientError, ER_FUNC_WRONG_ARG_COUNT, "SUBSTR",
-			 "1 or 2", argc);
-		context->is_aborted = true;
-		return;
-	}
-	if (mem_is_null(&argv[1]) || (argc == 3 && mem_is_null(&argv[2])))
-		return;
-	p0type = sql_value_type(&argv[0]);
-	p1 = mem_get_int_unsafe(&argv[1]);
-	if (p0type == MP_BIN) {
-		z = mem_as_bin(&argv[0]);
-		len = mem_len_unsafe(&argv[0]);
-		if (z == 0)
-			return;
-		assert(len == mem_len_unsafe(&argv[0]));
-	} else {
-		z = mem_as_ustr(&argv[0]);
-		if (z == 0)
-			return;
-		len = 0;
-		if (p1 < 0)
-			len = sql_utf8_char_count(z, mem_len_unsafe(&argv[0]));
-	}
-	if (argc == 3) {
-		p2 = mem_get_int_unsafe(&argv[2]);
-		if (p2 < 0) {
-			p2 = -p2;
-			negP2 = 1;
-		}
-	} else {
-		p2 = sql_context_db_handle(context)->
-		    aLimit[SQL_LIMIT_LENGTH];
-	}
-	if (p1 < 0) {
-		p1 += len;
-		if (p1 < 0) {
-			p2 += p1;
-			if (p2 < 0)
-				p2 = 0;
-			p1 = 0;
-		}
-	} else if (p1 > 0) {
-		p1--;
-	} else if (p2 > 0) {
-		p2--;
-	}
-	if (negP2) {
-		p1 -= p2;
-		if (p1 < 0) {
-			p2 += p1;
-			p1 = 0;
-		}
-	}
-	assert(p1 >= 0 && p2 >= 0);
-	if (p0type != MP_BIN) {
-		/*
-		 * In the code below 'cnt' and 'n_chars' is
-		 * used because '\0' is not supposed to be
-		 * end-of-string symbol.
-		 */
-		int byte_size = mem_len_unsafe(&argv[0]);
-		int n_chars = sql_utf8_char_count(z, byte_size);
-		int cnt = 0;
-		int i = 0;
-		while (cnt < n_chars && p1) {
-			SQL_UTF8_FWD_1(z, i, byte_size);
-			cnt++;
-			p1--;
-		}
-		z += i;
-		i = 0;
-		for (z2 = z; cnt < n_chars && p2; p2--) {
-			SQL_UTF8_FWD_1(z2, i, byte_size);
-			cnt++;
-		}
-		z2 += i;
-		mem_copy_str(context->pOut, (char *)z, z2 - z);
-	} else {
-		if (p1 + p2 > len) {
-			p2 = len - p1;
-			if (p2 < 0)
-				p2 = 0;
-		}
-		mem_copy_bin(context->pOut, (char *)&z[p1], p2);
-	}
-}
-
 /*
  * Implementation of the round() function
  */
@@ -1933,15 +1978,15 @@ static struct sql_func_definition definitions[] = {
 	{"SOUNDEX", 1, {FIELD_TYPE_STRING}, FIELD_TYPE_STRING, soundexFunc,
 	 NULL},
 	{"SUBSTR", 2, {FIELD_TYPE_STRING, FIELD_TYPE_INTEGER},
-	 FIELD_TYPE_STRING, substrFunc, NULL},
+	 FIELD_TYPE_STRING, func_substr_characters, NULL},
 	{"SUBSTR", 3,
 	 {FIELD_TYPE_STRING, FIELD_TYPE_INTEGER, FIELD_TYPE_INTEGER},
-	 FIELD_TYPE_STRING, substrFunc, NULL},
+	 FIELD_TYPE_STRING, func_substr_characters, NULL},
 	{"SUBSTR", 2, {FIELD_TYPE_VARBINARY, FIELD_TYPE_INTEGER},
-	 FIELD_TYPE_VARBINARY, substrFunc, NULL},
+	 FIELD_TYPE_VARBINARY, func_substr_octets, NULL},
 	{"SUBSTR", 3,
 	 {FIELD_TYPE_VARBINARY, FIELD_TYPE_INTEGER, FIELD_TYPE_INTEGER},
-	 FIELD_TYPE_VARBINARY, substrFunc, NULL},
+	 FIELD_TYPE_VARBINARY, func_substr_octets, NULL},
 	{"SUM", 1, {FIELD_TYPE_INTEGER}, FIELD_TYPE_INTEGER, step_sum, NULL},
 	{"SUM", 1, {FIELD_TYPE_DOUBLE}, FIELD_TYPE_DOUBLE, step_sum, NULL},
 	{"TOTAL", 1, {FIELD_TYPE_INTEGER}, FIELD_TYPE_DOUBLE, step_total,
diff --git a/test/sql-tap/func.test.lua b/test/sql-tap/func.test.lua
index 29e1c3de2..b52d5bd4c 100755
--- a/test/sql-tap/func.test.lua
+++ b/test/sql-tap/func.test.lua
@@ -139,7 +139,7 @@ test:do_execsql_test(
         SELECT substr(t1,-1,1) FROM tbl1 ORDER BY t1
     ]], {
         -- <func-2.3>
-        "e", "s", "m", "e", "s"
+        "", "", "", "", ""
         -- </func-2.3>
     })
 
@@ -149,7 +149,7 @@ test:do_execsql_test(
         SELECT substr(t1,-1,2) FROM tbl1 ORDER BY t1
     ]], {
         -- <func-2.4>
-        "e", "s", "m", "e", "s"
+        "", "", "", "", ""
         -- </func-2.4>
     })
 
@@ -159,7 +159,7 @@ test:do_execsql_test(
         SELECT substr(t1,-2,1) FROM tbl1 ORDER BY t1
     ]], {
         -- <func-2.5>
-        "e", "i", "a", "r", "i"
+        "", "", "", "", ""
         -- </func-2.5>
     })
 
@@ -169,7 +169,7 @@ test:do_execsql_test(
         SELECT substr(t1,-2,2) FROM tbl1 ORDER BY t1
     ]], {
         -- <func-2.6>
-        "ee", "is", "am", "re", "is"
+        "", "", "", "", ""
         -- </func-2.6>
     })
 
@@ -179,7 +179,7 @@ test:do_execsql_test(
         SELECT substr(t1,-4,2) FROM tbl1 ORDER BY t1
     ]], {
         -- <func-2.7>
-        "fr", "", "gr", "wa", "th"
+        "", "", "", "", ""
         -- </func-2.7>
     })
 
@@ -288,7 +288,7 @@ if ("ሴ" ~= "u1234") then
             SELECT substr(t1,-1,1) FROM tbl1 ORDER BY t1
         ]], {
             -- <func-3.8>
-            "8", "s", "s", "o"
+            "", "", "", ""
             -- </func-3.8>
         })
 
@@ -298,7 +298,7 @@ if ("ሴ" ~= "u1234") then
             SELECT substr(t1,-3,2) FROM tbl1 ORDER BY t1
         ]], {
             -- <func-3.9>
-            "F-", "er", "in", "ሴh"
+            "", "", "", ""
             -- </func-3.9>
         })
 
@@ -308,7 +308,7 @@ if ("ሴ" ~= "u1234") then
             SELECT substr(t1,-4,3) FROM tbl1 ORDER BY t1
         ]], {
             -- <func-3.10>
-            "TF-", "ter", "ain", "iሴh"
+            "", "", "", ""
             -- </func-3.10>
         })
 
diff --git a/test/sql-tap/func2.test.lua b/test/sql-tap/func2.test.lua
index 792f020f1..b786b4d96 100755
--- a/test/sql-tap/func2.test.lua
+++ b/test/sql-tap/func2.test.lua
@@ -162,7 +162,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -1)
     ]], {
         -- <func2-1.11>
-        "s"
+        "Supercalifragilisticexpialidocious"
         -- </func2-1.11>
     })
 
@@ -172,7 +172,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -2)
     ]], {
         -- <func2-1.12>
-        "us"
+        "Supercalifragilisticexpialidocious"
         -- </func2-1.12>
     })
 
@@ -182,7 +182,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -30)
     ]], {
         -- <func2-1.13>
-        "rcalifragilisticexpialidocious"
+        "Supercalifragilisticexpialidocious"
         -- </func2-1.13>
     })
 
@@ -344,7 +344,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -1, 1)
     ]], {
         -- <func2-1.25.1>
-        "s"
+        ""
         -- </func2-1.25.1>
     })
 
@@ -354,7 +354,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -1, 2)
     ]], {
         -- <func2-1.25.2>
-        "s"
+        ""
         -- </func2-1.25.2>
     })
 
@@ -364,7 +364,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -2, 1)
     ]], {
         -- <func2-1.26>
-        "u"
+        ""
         -- </func2-1.26>
     })
 
@@ -374,7 +374,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -30, 1)
     ]], {
         -- <func2-1.27>
-        "r"
+        ""
         -- </func2-1.27>
     })
 
@@ -394,7 +394,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -34, 1)
     ]], {
         -- <func2-1.28.1>
-        "S"
+        ""
         -- </func2-1.28.1>
     })
 
@@ -404,7 +404,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -34, 2)
     ]], {
         -- <func2-1.28.2>
-        "Su"
+        ""
         -- </func2-1.28.2>
     })
 
@@ -424,7 +424,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -35, 2)
     ]], {
         -- <func2-1.29.2>
-        "S"
+        ""
         -- </func2-1.29.2>
     })
 
@@ -464,11 +464,13 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -36, 3)
     ]], {
         -- <func2-1.30.3>
-        "S"
+        ""
         -- </func2-1.30.3>
     })
 
 -- p1 is 1-indexed, p2 length to return, p2<0 return p2 chars before p1
+local err = [[Failed to execute SQL statement: Length of the result cannot ]]..
+            [[be less than 0]]
 test:do_execsql_test(
     "func2-1.31.0",
     [[
@@ -479,23 +481,23 @@ test:do_execsql_test(
         -- </func2-1.31.0>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.31.1",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 0, -1)
     ]], {
         -- <func2-1.31.1>
-        ""
+        1, err
         -- </func2-1.31.1>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.31.2",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 0, -2)
     ]], {
         -- <func2-1.31.2>
-        ""
+        1, err
         -- </func2-1.31.2>
     })
 
@@ -509,13 +511,13 @@ test:do_execsql_test(
         -- </func2-1.32.0>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.32.1",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 1, -1)
     ]], {
         -- <func2-1.32.1>
-        ""
+        1, err
         -- </func2-1.32.1>
     })
 
@@ -529,23 +531,23 @@ test:do_execsql_test(
         -- </func2-1.33.0>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.33.1",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 2, -1)
     ]], {
         -- <func2-1.33.1>
-        "S"
+        1, err
         -- </func2-1.33.1>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.33.2",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 2, -2)
     ]], {
         -- <func2-1.33.2>
-        "S"
+        1, err
         -- </func2-1.33.2>
     })
 
@@ -559,63 +561,63 @@ test:do_execsql_test(
         -- </func2-1.34.0>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.34.1",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 3, -1)
     ]], {
         -- <func2-1.34.1>
-        "u"
+        1, err
         -- </func2-1.34.1>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.34.2",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 3, -2)
     ]], {
         -- <func2-1.34.2>
-        "Su"
+        1, err
         -- </func2-1.34.2>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.35.1",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 30, -1)
     ]], {
         -- <func2-1.35.1>
-        "o"
+        1, err
         -- </func2-1.35.1>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.35.2",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 30, -2)
     ]], {
         -- <func2-1.35.2>
-        "do"
+        1, err
         -- </func2-1.35.2>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.36",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 34, -1)
     ]], {
         -- <func2-1.36>
-        "u"
+        1, err
         -- </func2-1.36>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.37",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 35, -1)
     ]], {
         -- <func2-1.37>
-        "s"
+        1, err
         -- </func2-1.37>
     })
 
@@ -629,23 +631,23 @@ test:do_execsql_test(
         -- </func2-1.38.0>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.38.1",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 36, -1)
     ]], {
         -- <func2-1.38.1>
-        ""
+        1, err
         -- </func2-1.38.1>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.38.2",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 36, -2)
     ]], {
         -- <func2-1.38.2>
-        "s"
+        1, err
         -- </func2-1.38.2>
     })
 
@@ -993,7 +995,7 @@ if ("ሴ" ~= "u1234")
             SELECT SUBSTR('ሴ', -1, 1)
         ]], {
             -- <func2-2.8.1>
-            "ሴ"
+            ""
             -- </func2-2.8.1>
         })
 
@@ -1003,7 +1005,7 @@ if ("ሴ" ~= "u1234")
             SELECT SUBSTR('ሴ', -1, 2)
         ]], {
             -- <func2-2.8.2>
-            "ሴ"
+            ""
             -- </func2-2.8.2>
         })
 
@@ -1130,21 +1132,21 @@ test:do_test(
     function()
         local blob = test:execsql "SELECT SUBSTR(x'1234', -1, 1)"
         return bin_to_hex(test.lindex(blob, 0))
-    end, "34")
+    end, "")
 
 test:do_test(
     "func2-3.4.2",
     function()
         local blob = test:execsql "SELECT SUBSTR(x'1234', -1, 2)"
         return bin_to_hex(test.lindex(blob, 0))
-    end, "34")
+    end, "")
 
 test:do_test(
     "func2-3.4.3",
     function()
         local blob = test:execsql "SELECT SUBSTR(x'1234', -1, 3)"
         return bin_to_hex(test.lindex(blob, 0))
-    end, "34")
+    end, "12")
 
 test:do_test(
     "func2-3.5.0",
@@ -1158,21 +1160,21 @@ test:do_test(
     function()
         local blob = test:execsql "SELECT SUBSTR(x'1234', -2, 1)"
         return bin_to_hex(test.lindex(blob, 0))
-    end, "12")
+    end, "")
 
 test:do_test(
     "func2-3.5.2",
     function()
         local blob = test:execsql "SELECT SUBSTR(x'1234', -2, 2)"
         return bin_to_hex(test.lindex(blob, 0))
-    end, "1234")
+    end, "")
 
 test:do_test(
     "func2-3.5.3",
     function()
         local blob = test:execsql "SELECT SUBSTR(x'1234', -2, 3)"
         return bin_to_hex(test.lindex(blob, 0))
-    end, "1234")
+    end, "")
 
 test:do_test(
     "func2-3.6.0",
@@ -1181,26 +1183,28 @@ test:do_test(
         return bin_to_hex(test.lindex(blob, 0))
     end, "")
 
+local err = [[Failed to execute SQL statement: Length of the result cannot ]]..
+            [[be less than 0]]
 test:do_test(
     "func2-3.6.1",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', -1, -1)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "12")
+        return test:catchsql("SELECT SUBSTR(x'1234', -1, -1)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.6.2",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', -1, -2)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "12")
+        return test:catchsql("SELECT SUBSTR(x'1234', -1, -2)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.6.3",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', -1, -3)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "12")
+        return test:catchsql("SELECT SUBSTR(x'1234', -1, -3)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.7.0",
@@ -1212,16 +1216,16 @@ test:do_test(
 test:do_test(
     "func2-3.7.1",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', -2, -1)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "")
+        return test:catchsql("SELECT SUBSTR(x'1234', -2, -1)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.7.2",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', -2, -2)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "")
+        return test:catchsql("SELECT SUBSTR(x'1234', -2, -2)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.8.0",
@@ -1233,16 +1237,16 @@ test:do_test(
 test:do_test(
     "func2-3.8.1",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', 1, -1)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "")
+        return test:catchsql("SELECT SUBSTR(x'1234', 1, -1)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.8.2",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', 1, -2)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "")
+        return test:catchsql("SELECT SUBSTR(x'1234', 1, -2)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.9.0",
@@ -1254,17 +1258,15 @@ test:do_test(
 test:do_test(
     "func2-3.9.1",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', 2, -1)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "12")
+        return test:catchsql("SELECT SUBSTR(x'1234', 2, -2)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.9.2",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', 2, -2)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "12")
-
-
+        return test:catchsql("SELECT SUBSTR(x'1234', 2, -2)")
+    end,
+        {1, err})
 
 test:finish_test()
diff --git a/test/sql-tap/substr.test.lua b/test/sql-tap/substr.test.lua
index e7e6d7aca..45aae8506 100755
--- a/test/sql-tap/substr.test.lua
+++ b/test/sql-tap/substr.test.lua
@@ -1,6 +1,6 @@
 #!/usr/bin/env tarantool
 local test = require("sqltester")
-test:plan(93)
+test:plan(85)
 
 --!./tcltestrunner.lua
 -- 2007 May 14
@@ -74,17 +74,11 @@ substr_test("1.2", "abcdefg","2","1","b")
 substr_test("1.3", "abcdefg","1","2","ab")
 substr_test("1.4", "abcdefg","1","100","abcdefg")
 substr_test("1.5", "abcdefg","0","2","a")
-substr_test("1.6", "abcdefg","-1","1","g")
-substr_test("1.7", "abcdefg","-1","10","g")
-substr_test("1.8", "abcdefg","-5","3","cde")
-substr_test("1.9", "abcdefg","-7","3","abc")
-substr_test("1.10", "abcdefg","-100","98","abcde")
-substr_test("1.11", "abcdefg","5","-1","d")
-substr_test("1.12", "abcdefg","5","-4","abcd")
-substr_test("1.13", "abcdefg","5","-5","abcd")
-substr_test("1.14", "abcdefg","-5","-1","b")
-substr_test("1.15", "abcdefg","-5","-2","ab")
-substr_test("1.16", "abcdefg","-5","-3","ab")
+substr_test("1.6", "abcdefg","-1","1","")
+substr_test("1.7", "abcdefg","-1","10","abcdefg")
+substr_test("1.8", "abcdefg","-5","3","")
+substr_test("1.9", "abcdefg","-7","3","")
+substr_test("1.10", "abcdefg","-100","98","")
 substr_test("1.17", "abcdefg","100","200","")
 substr_test("1.18", "abcdefg","200","100","")
 -- Make sure NULL is returned if any parameter is NULL
@@ -144,21 +138,20 @@ test:do_test(
 substr_test("2.1", "ሴ⍅㑖","1","1","ሴ")
 substr_test("2.2", "ሴ⍅㑖","2","1","⍅")
 substr_test("2.3", "ሴ⍅㑖","1","2","ሴ⍅")
-substr_test("2.4", "ሴ⍅㑖","-1","1","㑖")
-substr_test("2.5", "aሴb⍅c㑖c","-5","3","b⍅c")
-substr_test("2.6", "aሴb⍅c㑖c","-2","-3","b⍅c")
+substr_test("2.4", "ሴ⍅㑖","-1","1","")
+substr_test("2.5", "aሴb⍅c㑖c","-5","3","")
 -- Basic functionality for BLOBs
 --
 subblob_test("3.1", "61626364656667","1","1","61")
 subblob_test("3.2", "61626364656667","2","1","62")
 subblob_test("3.3", "61626364656667","1","2","6162")
 subblob_test("3.4", "61626364656667","1","100","61626364656667")
-subblob_test("3.5", "61626364656667","0","2","61")
-subblob_test("3.6", "61626364656667","-1","1","67")
-subblob_test("3.7", "61626364656667","-1","10","67")
-subblob_test("3.8", "61626364656667","-5","3","636465")
-subblob_test("3.9", "61626364656667","-7","3","616263")
-subblob_test("3.10", "61626364656667","-100","98","6162636465")
+subblob_test("3.5", "61626364656667", "0", "2", "61")
+subblob_test("3.6", "61626364656667", "-1", "1", "")
+subblob_test("3.7", "61626364656667", "-1", "10", "61626364656667")
+subblob_test("3.8", "61626364656667", "-5", "3", "")
+subblob_test("3.9", "61626364656667","-7","3", "")
+subblob_test("3.10", "61626364656667", "-100", "98", "")
 subblob_test("3.11", "61626364656667","100","200","")
 subblob_test("3.12", "61626364656667","200","100","")
 -- If these blobs were strings, then they would contain multi-byte
@@ -168,9 +161,9 @@ subblob_test("3.12", "61626364656667","200","100","")
 subblob_test("4.1", "61E188B462E28D8563E3919663","1","1","61")
 subblob_test("4.2", "61E188B462E28D8563E3919663","2","1","E1")
 subblob_test("4.3", "61E188B462E28D8563E3919663","1","2","61E1")
-subblob_test("4.4", "61E188B462E28D8563E3919663","-2","1","96")
-subblob_test("4.5", "61E188B462E28D8563E3919663","-5","4","63E39196")
-subblob_test("4.6", "61E188B462E28D8563E3919663","-100","98","61E188B462E28D8563E391")
+subblob_test("4.4", "61E188B462E28D8563E3919663", "-2", "1", "")
+subblob_test("4.5", "61E188B462E28D8563E3919663", "-5", "4", "")
+subblob_test("4.6", "61E188B462E28D8563E3919663", "-100", "98", "")
 -- Two-argument SUBSTR
 --
 local function substr_2_test(id, string, idx, result)
@@ -193,7 +186,85 @@ local function substr_2_test(id, string, idx, result)
 end
 
 substr_2_test("5.1","abcdefghijklmnop","5","efghijklmnop")
-substr_2_test("5.2","abcdef","-5","bcdef")
+substr_2_test("5.2","abcdef","-5","abcdef")
 
+--
+-- gh-4145: Make sure SUBSTR() throws an error if the third argument is
+-- negative.
+--
+test:do_catchsql_test(
+    "substr-6.1",
+    [[
+        SELECT SUBSTR('12345', 1, -1);
+    ]],
+    {
+        1, [[Failed to execute SQL statement: ]]..
+           [[Length of the result cannot be less than 0]]
+    }
+)
+
+test:do_catchsql_test(
+    "substr-6.2",
+    [[
+        SELECT SUBSTR(x'3132333435', 1, -1);
+    ]],
+    {
+        1, [[Failed to execute SQL statement: ]]..
+           [[Length of the result cannot be less than 0]]
+    }
+)
+
+-- gh-4145: Make sure that SUBSTR() works according to ANSI.
+
+--
+-- Make sure SUBSTR() returns "" if the sum of the second and third arguments is
+-- 1 or less.
+--
+test:do_execsql_test(
+    "builtins-6.3",
+    [[
+        SELECT SUBSTR('asdfg', -10, 5), SUBSTR('asdfg', -4, 5);
+    ]],
+    {
+        '', ''
+    }
+)
+
+--
+-- Make sure that if the sum of the second and third arguments is more than 1
+-- and the second argument is negative, the result starts from the start of the
+-- string and length of the result will be one less than sum of the  second and
+-- third arguments.
+--
+test:do_execsql_test(
+    "builtins-6.4",
+    [[
+        SELECT SUBSTR('123456789', -5, 10);
+    ]],
+    {
+        '1234'
+    }
+)
+
+-- Make sure SUBSTR() can work with big INTEGERs.
+test:do_execsql_test(
+    "builtins-6.5",
+    [[
+        SELECT SUBSTR('123456789', -9223372036854775808, 9223372036854775812);
+    ]],
+    {
+        '123'
+    }
+)
+
+test:do_execsql_test(
+    "builtins-6.6",
+    [[
+        SELECT SUBSTR('123456789', 0, 18000000000000000000);
+    ]],
+    {
+        '123456789'
+    }
+)
 
 test:finish_test()
-- 
2.25.1


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [Tarantool-patches] [PATCH v1 8/8] sql: refactor LIKE() function
  2021-11-11 10:45 [Tarantool-patches] [PATCH v1 0/8] Rework standard function Mergen Imeev via Tarantool-patches
                   ` (6 preceding siblings ...)
  2021-11-11 10:45 ` [Tarantool-patches] [PATCH v1 7/8] sql: rework SUBSTR() function Mergen Imeev via Tarantool-patches
@ 2021-11-11 10:45 ` Mergen Imeev via Tarantool-patches
  2021-11-11 10:59 ` [Tarantool-patches] [PATCH v1 0/8] Rework standard function Kirill Yukhin via Tarantool-patches
  8 siblings, 0 replies; 15+ messages in thread
From: Mergen Imeev via Tarantool-patches @ 2021-11-11 10:45 UTC (permalink / raw)
  To: kyukhin; +Cc: tarantool-patches

Part of #4145
---
 src/box/sql/func.c | 51 ++++++++++++++++------------------------------
 1 file changed, 17 insertions(+), 34 deletions(-)

diff --git a/src/box/sql/func.c b/src/box/sql/func.c
index 7e71a757b..868d51145 100644
--- a/src/box/sql/func.c
+++ b/src/box/sql/func.c
@@ -1271,63 +1271,46 @@ likeFunc(sql_context *context, int argc, struct Mem *argv)
 {
 	u32 escape = SQL_END_OF_STRING;
 	int nPat;
-	if (argc != 2 && argc != 3) {
-		diag_set(ClientError, ER_FUNC_WRONG_ARG_COUNT,
-			 "LIKE", "2 or 3", argc);
-		context->is_aborted = true;
-		return;
-	}
-	sql *db = sql_context_db_handle(context);
-	int rhs_type = sql_value_type(&argv[0]);
-	int lhs_type = sql_value_type(&argv[1]);
-
-	if (lhs_type != MP_STR || rhs_type != MP_STR) {
-		if (lhs_type == MP_NIL || rhs_type == MP_NIL)
-			return;
-		const char *str = rhs_type != MP_STR ?
-				  mem_str(&argv[0]) : mem_str(&argv[1]);
-		diag_set(ClientError, ER_INCONSISTENT_TYPES, "string", str);
-		context->is_aborted = true;
+	assert(argc == 2 || argc == 3);
+	if (mem_is_any_null(&argv[0], &argv[1]))
 		return;
-	}
-	const char *zB = mem_as_str0(&argv[0]);
-	const char *zA = mem_as_str0(&argv[1]);
-	const char *zB_end = zB + mem_len_unsafe(&argv[0]);
-	const char *zA_end = zA + mem_len_unsafe(&argv[1]);
+	assert(mem_is_str(&argv[0]) && mem_is_str(&argv[1]));
+	const char *zB = argv[0].z;
+	const char *zA = argv[1].z;
+	const char *zB_end = zB + argv[0].n;
+	const char *zA_end = zA + argv[1].n;
 
 	/*
 	 * Limit the length of the LIKE pattern to avoid problems
 	 * of deep recursion and N*N behavior in
 	 * sql_utf8_pattern_compare().
 	 */
-	nPat = mem_len_unsafe(&argv[0]);
-	testcase(nPat == db->aLimit[SQL_LIMIT_LIKE_PATTERN_LENGTH]);
-	testcase(nPat == db->aLimit[SQL_LIMIT_LIKE_PATTERN_LENGTH] + 1);
-	if (nPat > db->aLimit[SQL_LIMIT_LIKE_PATTERN_LENGTH]) {
+	nPat = argv[0].n;
+	if (nPat > sql_get()->aLimit[SQL_LIMIT_LIKE_PATTERN_LENGTH]) {
 		diag_set(ClientError, ER_SQL_EXECUTE, "LIKE pattern is too "\
 			 "complex");
 		context->is_aborted = true;
 		return;
 	}
-	/* Encoding did not change */
-	assert(zB == mem_as_str0(&argv[0]));
 
 	if (argc == 3) {
+		if (mem_is_null(&argv[2]))
+			return;
 		/*
 		 * The escape character string must consist of a
 		 * single UTF-8 character. Otherwise, return an
 		 * error.
 		 */
-		const unsigned char *zEsc = mem_as_ustr(&argv[2]);
-		if (zEsc == 0)
-			return;
-		if (sql_utf8_char_count(zEsc, mem_len_unsafe(&argv[2])) != 1) {
+		const char *str = argv[2].z;
+		int pos = 0;
+		int end = argv[2].n;
+		U8_NEXT((uint8_t *)str, pos, end, escape);
+		if (pos != end || end == 0) {
 			diag_set(ClientError, ER_SQL_EXECUTE, "ESCAPE "\
 				 "expression must be a single character");
 			context->is_aborted = true;
 			return;
 		}
-		escape = sqlUtf8Read(&zEsc);
 	}
 	if (!zA || !zB)
 		return;
@@ -1342,7 +1325,7 @@ likeFunc(sql_context *context, int argc, struct Mem *argv)
 		context->is_aborted = true;
 		return;
 	}
-	sql_result_bool(context, res == MATCH);
+	mem_set_bool(context->pOut, res == MATCH);
 }
 
 /**
-- 
2.25.1


^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [Tarantool-patches] [PATCH v1 0/8] Rework standard function
  2021-11-11 10:45 [Tarantool-patches] [PATCH v1 0/8] Rework standard function Mergen Imeev via Tarantool-patches
                   ` (7 preceding siblings ...)
  2021-11-11 10:45 ` [Tarantool-patches] [PATCH v1 8/8] sql: refactor LIKE() function Mergen Imeev via Tarantool-patches
@ 2021-11-11 10:59 ` Kirill Yukhin via Tarantool-patches
  8 siblings, 0 replies; 15+ messages in thread
From: Kirill Yukhin via Tarantool-patches @ 2021-11-11 10:59 UTC (permalink / raw)
  To: imeevma; +Cc: tarantool-patches


Hello,

On 11 ноя 13:45, imeevma@tarantool.org wrote:
> This patch refactors all non-aggregate standard functions and makes these
> functions work according to ANSI rules, if it is possible. However, the ANSI
> specific syntax for these functions will be presented later.
> 
> https://github.com/tarantool/tarantool/issues/4145
> https://github.com/tarantool/tarantool/tree/imeevma/gh-4145-rework-sql-built-in-funcs

LGTM. I've checked your patchset into master.

--
Regards, Kirill Yukhin

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [Tarantool-patches] [PATCH v1 7/8] sql: rework SUBSTR() function
  2021-10-28 22:13       ` Vladislav Shpilevoy via Tarantool-patches
@ 2021-11-01 10:45         ` Mergen Imeev via Tarantool-patches
  0 siblings, 0 replies; 15+ messages in thread
From: Mergen Imeev via Tarantool-patches @ 2021-11-01 10:45 UTC (permalink / raw)
  To: Vladislav Shpilevoy; +Cc: tarantool-patches

Thank you for the review! My answer, diff and new patch below. Also, I replaced
ucnv_getNextUChar() by U8_NEXT().

On Fri, Oct 29, 2021 at 12:13:05AM +0200, Vladislav Shpilevoy wrote:
> Thanks for the fixes!
> 
> > diff --git a/src/box/sql/func.c b/src/box/sql/func.c
> > index 80b075dcf..65bf03250 100644
> > --- a/src/box/sql/func.c
> > +++ b/src/box/sql/func.c
> > +
> > +static void
> > +func_substr_octets(struct sql_context *ctx, int argc, struct Mem *argv)
> > +{
> > +	assert(argc == 2 || argc == 3);
> > +	if (mem_is_any_null(&argv[0], &argv[1]))
> > +		return;
> > +	assert(mem_is_bytes(&argv[0]) && mem_is_int(&argv[1]));
> > +
> > +	bool is_str = mem_is_str(&argv[0]);
> > +	uint64_t size = argv[0].n;
> > +
> > +	if (argc == 2) {
> > +		uint64_t start = mem_is_uint(&argv[1]) && argv[1].u.u > 1 ?
> > +				 argv[1].u.u - 1 : 0;
> > +		if (start >= size)
> > +			return return_empty_str(ctx, is_str);
> > +		char *s = &argv[0].z[start];
> > +		uint64_t n = size - start;
> > +		ctx->is_aborted = is_str ? mem_copy_str(ctx->pOut, s, n) != 0 :
> > +				  mem_copy_bin(ctx->pOut, s, n) != 0;
> > +		return;
> > +	}
> > +
> > +	assert(argc == 3);
> > +	if (mem_is_null(&argv[2]))
> > +		return;
> > +	assert(mem_is_int(&argv[2]));
> > +	if (!mem_is_uint(&argv[2])) {
> > +		diag_set(ClientError, ER_SQL_EXECUTE, "Length of the result "
> > +			 "cannot be less than 0");
> > +		ctx->is_aborted = true;
> > +		return;
> > +	}
> > +	uint64_t start;
> > +	uint64_t length;
> > +	if (substr_normalize(argv[1].u.i, !mem_is_uint(&argv[1]), argv[2].u.u,
> > +	    &start, &length) != 0) {
> 
> The second line of the call is misaligned.
Fixed.

Diff:

diff --git a/src/box/sql/func.c b/src/box/sql/func.c
index a76b023eb..7e71a757b 100644
--- a/src/box/sql/func.c
+++ b/src/box/sql/func.c
@@ -623,8 +623,12 @@ func_substr_octets(struct sql_context *ctx, int argc, struct Mem *argv)
 	if (argc == 2) {
 		uint64_t start = mem_is_uint(&argv[1]) && argv[1].u.u > 1 ?
 				 argv[1].u.u - 1 : 0;
-		if (start >= size)
-			return return_empty_str(ctx, is_str);
+		if (start >= size) {
+			if (is_str)
+				return mem_set_str0_static(ctx->pOut, "");
+			else
+				return mem_set_bin_static(ctx->pOut, "", 0);
+		}
 		char *s = &argv[0].z[start];
 		uint64_t n = size - start;
 		ctx->is_aborted = is_str ? mem_copy_str(ctx->pOut, s, n) != 0 :
@@ -645,12 +649,16 @@ func_substr_octets(struct sql_context *ctx, int argc, struct Mem *argv)
 	uint64_t start;
 	uint64_t length;
 	if (substr_normalize(argv[1].u.i, !mem_is_uint(&argv[1]), argv[2].u.u,
-	    &start, &length) != 0) {
+			     &start, &length) != 0) {
 		ctx->is_aborted = true;
 		return;
 	}
-	if (start >= size || length == 0)
-		return return_empty_str(ctx, is_str);
+	if (start >= size || length == 0) {
+		if (is_str)
+			return mem_set_str0_static(ctx->pOut, "");
+		else
+			return mem_set_bin_static(ctx->pOut, "", 0);
+	}
 	char *str = &argv[0].z[start];
 	uint64_t len = MIN(size - start, length);
 	ctx->is_aborted = is_str ? mem_copy_str(ctx->pOut, str, len) != 0 :
@@ -666,17 +674,19 @@ func_substr_characters(struct sql_context *ctx, int argc, struct Mem *argv)
 		return;
 	assert(mem_is_str(&argv[0]) && mem_is_int(&argv[1]));
 
-	UErrorCode err = U_ZERO_ERROR;
-	const char *pos = argv[0].z;
-	const char *end = argv[0].z + argv[0].n;
+	const char *str = argv[0].z;
+	int pos = 0;
+	int end = argv[0].n;
 	if (argc == 2) {
 		uint64_t start = mem_is_uint(&argv[1]) && argv[1].u.u > 1 ?
 				 argv[1].u.u - 1 : 0;
-		for (uint64_t i = 0; i < start && pos < end; ++i)
-			ucnv_getNextUChar(icu_utf8_conv, &pos, end, &err);
+		for (uint64_t i = 0; i < start && pos < end; ++i) {
+			UChar32 c;
+			U8_NEXT((uint8_t *)str, pos, end, c);
+		}
 		if (pos == end)
 			return mem_set_str_static(ctx->pOut, "", 0);
-		if (mem_copy_str(ctx->pOut, pos, end - pos) != 0)
+		if (mem_copy_str(ctx->pOut, str + pos, end - pos) != 0)
 			ctx->is_aborted = true;
 		return;
 	}
@@ -694,22 +704,27 @@ func_substr_characters(struct sql_context *ctx, int argc, struct Mem *argv)
 	uint64_t start;
 	uint64_t length;
 	if (substr_normalize(argv[1].u.i, !mem_is_uint(&argv[1]), argv[2].u.u,
-	    &start, &length) != 0) {
+			     &start, &length) != 0) {
 		ctx->is_aborted = true;
 		return;
 	}
 	if (length == 0)
 		return mem_set_str_static(ctx->pOut, "", 0);
 
-	for (uint64_t i = 0; i < start && err == U_ZERO_ERROR; ++i)
-		ucnv_getNextUChar(icu_utf8_conv, &pos, end, &err);
-	const char *cur = pos;
-	for (uint64_t i = 0; i < length && cur < end; ++i)
-		ucnv_getNextUChar(icu_utf8_conv, &cur, end, &err);
-	if (err != U_ZERO_ERROR || cur == pos)
+	for (uint64_t i = 0; i < start && pos < end; ++i) {
+		UChar32 c;
+		U8_NEXT((uint8_t *)str, pos, end, c);
+	}
+	if (pos == end)
 		return mem_set_str_static(ctx->pOut, "", 0);
 
-	if (mem_copy_str(ctx->pOut, pos, cur - pos) != 0)
+	int cur = pos;
+	for (uint64_t i = 0; i < length && cur < end; ++i) {
+		UChar32 c;
+		U8_NEXT((uint8_t *)str, cur, end, c);
+	}
+	assert(cur > pos);
+	if (mem_copy_str(ctx->pOut, str + pos, cur - pos) != 0)
 		ctx->is_aborted = true;
 }


New patch:


commit 56a7a57544cebcbf2992fe4543a8b4a30cdc3f67
Author: Mergen Imeev <imeevma@gmail.com>
Date:   Mon Sep 27 10:15:14 2021 +0300

    sql: rework SUBSTR() function
    
    This patch makes SUBSTR() work according to ANSI rules for SUBSTRING()
    function. Also, SUBSTR() can now work correctly with large INTEGER
    values. The SUBSTR() syntax has not changed.
    
    Part of #4145
    
    @TarantoolBot document
    Title: SUBSTR() function
    
    SUBSTR() now works according to the ANSI rules for SUBSTRING().
    
    Rules for SUBSTR() with 2 arguments:
    1) let the first argument be VALUE, and the second argument be START;
    2) VALUE should be STRING or VARBINARY, START should be INTEGER;
    3) if any of arguments is NULL, NULL is returned;
    4) let POS be MAX(START - 1, 0), END be length of the VALUE;
    5) if POS >= END, the result is empty string;
    6) if POS < END, the result will be substring of VALUE, starting from
       the position POS to the position END.
    
    Rules for SUBSTR() with 3 arguments:
    1) let the first argument be VALUE, the second argument be START, and
       the third argument be LENGTH;
    2) VALUE should be STRING or VARBINARY, START and LENGTH should be
       INTEGERs;
    3) if any of arguments is NULL, NULL is returned;
    4) if LENGTH < 0, an error is thrown;
    5) let POS be MAX(START - 1, 0), END be START + LENGTH - 1;
    6) if POS >= END, the result is empty string;
    7) if POS < END, the result will be substring of VALUE, starting from
       the position POS to the position END.

diff --git a/src/box/sql/func.c b/src/box/sql/func.c
index 7914d2ec7..7e71a757b 100644
--- a/src/box/sql/func.c
+++ b/src/box/sql/func.c
@@ -573,6 +573,161 @@ func_position_characters(struct sql_context *ctx, int argc, struct Mem *argv)
 	return mem_set_uint(ctx->pOut, 0);
 }
 
+/** Implementation of the SUBSTR() function. */
+int
+substr_normalize(int64_t base_start, bool is_start_neg, uint64_t base_length,
+		 uint64_t *start, uint64_t *length)
+{
+	if (!is_start_neg && base_start > 0) {
+		*start = (uint64_t)base_start - 1;
+		*length = base_length;
+		return 0;
+	}
+	*start = 0;
+	if (base_length == 0) {
+		*length = 0;
+		return 0;
+	}
+	/*
+	 * We are subtracting 1 from base_length instead of subtracting from
+	 * base_start, since base_start can be INT64_MIN. At the same time,
+	 * base_length is not less than 1.
+	 */
+	int64_t a = base_start;
+	int64_t b = (int64_t)(base_length - 1);
+	int64_t res;
+	bool is_neg;
+	/*
+	 * Integer cannot overflow since non-positive value is added to positive
+	 * value.
+	 */
+	if (sql_add_int(a, a != 0, b, false, &res, &is_neg) != 0) {
+		diag_set(ClientError, ER_SQL_EXECUTE, "integer is overflowed");
+		return -1;
+	}
+	*length = is_neg ? 0 : (uint64_t)res;
+	return 0;
+}
+
+static void
+func_substr_octets(struct sql_context *ctx, int argc, struct Mem *argv)
+{
+	assert(argc == 2 || argc == 3);
+	if (mem_is_any_null(&argv[0], &argv[1]))
+		return;
+	assert(mem_is_bytes(&argv[0]) && mem_is_int(&argv[1]));
+
+	bool is_str = mem_is_str(&argv[0]);
+	uint64_t size = argv[0].n;
+
+	if (argc == 2) {
+		uint64_t start = mem_is_uint(&argv[1]) && argv[1].u.u > 1 ?
+				 argv[1].u.u - 1 : 0;
+		if (start >= size) {
+			if (is_str)
+				return mem_set_str0_static(ctx->pOut, "");
+			else
+				return mem_set_bin_static(ctx->pOut, "", 0);
+		}
+		char *s = &argv[0].z[start];
+		uint64_t n = size - start;
+		ctx->is_aborted = is_str ? mem_copy_str(ctx->pOut, s, n) != 0 :
+				  mem_copy_bin(ctx->pOut, s, n) != 0;
+		return;
+	}
+
+	assert(argc == 3);
+	if (mem_is_null(&argv[2]))
+		return;
+	assert(mem_is_int(&argv[2]));
+	if (!mem_is_uint(&argv[2])) {
+		diag_set(ClientError, ER_SQL_EXECUTE, "Length of the result "
+			 "cannot be less than 0");
+		ctx->is_aborted = true;
+		return;
+	}
+	uint64_t start;
+	uint64_t length;
+	if (substr_normalize(argv[1].u.i, !mem_is_uint(&argv[1]), argv[2].u.u,
+			     &start, &length) != 0) {
+		ctx->is_aborted = true;
+		return;
+	}
+	if (start >= size || length == 0) {
+		if (is_str)
+			return mem_set_str0_static(ctx->pOut, "");
+		else
+			return mem_set_bin_static(ctx->pOut, "", 0);
+	}
+	char *str = &argv[0].z[start];
+	uint64_t len = MIN(size - start, length);
+	ctx->is_aborted = is_str ? mem_copy_str(ctx->pOut, str, len) != 0 :
+			  mem_copy_bin(ctx->pOut, str, len) != 0;
+}
+
+static void
+func_substr_characters(struct sql_context *ctx, int argc, struct Mem *argv)
+{
+	assert(argc == 2 || argc == 3);
+	(void)argc;
+	if (mem_is_any_null(&argv[0], &argv[1]))
+		return;
+	assert(mem_is_str(&argv[0]) && mem_is_int(&argv[1]));
+
+	const char *str = argv[0].z;
+	int pos = 0;
+	int end = argv[0].n;
+	if (argc == 2) {
+		uint64_t start = mem_is_uint(&argv[1]) && argv[1].u.u > 1 ?
+				 argv[1].u.u - 1 : 0;
+		for (uint64_t i = 0; i < start && pos < end; ++i) {
+			UChar32 c;
+			U8_NEXT((uint8_t *)str, pos, end, c);
+		}
+		if (pos == end)
+			return mem_set_str_static(ctx->pOut, "", 0);
+		if (mem_copy_str(ctx->pOut, str + pos, end - pos) != 0)
+			ctx->is_aborted = true;
+		return;
+	}
+
+	assert(argc == 3);
+	if (mem_is_null(&argv[2]))
+		return;
+	assert(mem_is_int(&argv[2]));
+	if (!mem_is_uint(&argv[2])) {
+		diag_set(ClientError, ER_SQL_EXECUTE, "Length of the result "
+			 "cannot be less than 0");
+		ctx->is_aborted = true;
+		return;
+	}
+	uint64_t start;
+	uint64_t length;
+	if (substr_normalize(argv[1].u.i, !mem_is_uint(&argv[1]), argv[2].u.u,
+			     &start, &length) != 0) {
+		ctx->is_aborted = true;
+		return;
+	}
+	if (length == 0)
+		return mem_set_str_static(ctx->pOut, "", 0);
+
+	for (uint64_t i = 0; i < start && pos < end; ++i) {
+		UChar32 c;
+		U8_NEXT((uint8_t *)str, pos, end, c);
+	}
+	if (pos == end)
+		return mem_set_str_static(ctx->pOut, "", 0);
+
+	int cur = pos;
+	for (uint64_t i = 0; i < length && cur < end; ++i) {
+		UChar32 c;
+		U8_NEXT((uint8_t *)str, cur, end, c);
+	}
+	assert(cur > pos);
+	if (mem_copy_str(ctx->pOut, str + pos, cur - pos) != 0)
+		ctx->is_aborted = true;
+}
+
 static const unsigned char *
 mem_as_ustr(struct Mem *mem)
 {
@@ -770,116 +925,6 @@ printfFunc(struct sql_context *context, int argc, struct Mem *argv)
 	}
 }
 
-/*
- * Implementation of the substr() function.
- *
- * substr(x,p1,p2)  returns p2 characters of x[] beginning with p1.
- * p1 is 1-indexed.  So substr(x,1,1) returns the first character
- * of x.  If x is text, then we actually count UTF-8 characters.
- * If x is a blob, then we count bytes.
- *
- * If p1 is negative, then we begin abs(p1) from the end of x[].
- *
- * If p2 is negative, return the p2 characters preceding p1.
- */
-static void
-substrFunc(struct sql_context *context, int argc, struct Mem *argv)
-{
-	const unsigned char *z;
-	const unsigned char *z2;
-	int len;
-	int p0type;
-	int64_t p1, p2;
-	int negP2 = 0;
-
-	if (argc != 2 && argc != 3) {
-		diag_set(ClientError, ER_FUNC_WRONG_ARG_COUNT, "SUBSTR",
-			 "1 or 2", argc);
-		context->is_aborted = true;
-		return;
-	}
-	if (mem_is_null(&argv[1]) || (argc == 3 && mem_is_null(&argv[2])))
-		return;
-	p0type = sql_value_type(&argv[0]);
-	p1 = mem_get_int_unsafe(&argv[1]);
-	if (p0type == MP_BIN) {
-		z = mem_as_bin(&argv[0]);
-		len = mem_len_unsafe(&argv[0]);
-		if (z == 0)
-			return;
-		assert(len == mem_len_unsafe(&argv[0]));
-	} else {
-		z = mem_as_ustr(&argv[0]);
-		if (z == 0)
-			return;
-		len = 0;
-		if (p1 < 0)
-			len = sql_utf8_char_count(z, mem_len_unsafe(&argv[0]));
-	}
-	if (argc == 3) {
-		p2 = mem_get_int_unsafe(&argv[2]);
-		if (p2 < 0) {
-			p2 = -p2;
-			negP2 = 1;
-		}
-	} else {
-		p2 = sql_context_db_handle(context)->
-		    aLimit[SQL_LIMIT_LENGTH];
-	}
-	if (p1 < 0) {
-		p1 += len;
-		if (p1 < 0) {
-			p2 += p1;
-			if (p2 < 0)
-				p2 = 0;
-			p1 = 0;
-		}
-	} else if (p1 > 0) {
-		p1--;
-	} else if (p2 > 0) {
-		p2--;
-	}
-	if (negP2) {
-		p1 -= p2;
-		if (p1 < 0) {
-			p2 += p1;
-			p1 = 0;
-		}
-	}
-	assert(p1 >= 0 && p2 >= 0);
-	if (p0type != MP_BIN) {
-		/*
-		 * In the code below 'cnt' and 'n_chars' is
-		 * used because '\0' is not supposed to be
-		 * end-of-string symbol.
-		 */
-		int byte_size = mem_len_unsafe(&argv[0]);
-		int n_chars = sql_utf8_char_count(z, byte_size);
-		int cnt = 0;
-		int i = 0;
-		while (cnt < n_chars && p1) {
-			SQL_UTF8_FWD_1(z, i, byte_size);
-			cnt++;
-			p1--;
-		}
-		z += i;
-		i = 0;
-		for (z2 = z; cnt < n_chars && p2; p2--) {
-			SQL_UTF8_FWD_1(z2, i, byte_size);
-			cnt++;
-		}
-		z2 += i;
-		mem_copy_str(context->pOut, (char *)z, z2 - z);
-	} else {
-		if (p1 + p2 > len) {
-			p2 = len - p1;
-			if (p2 < 0)
-				p2 = 0;
-		}
-		mem_copy_bin(context->pOut, (char *)&z[p1], p2);
-	}
-}
-
 /*
  * Implementation of the round() function
  */
@@ -1933,15 +1978,15 @@ static struct sql_func_definition definitions[] = {
 	{"SOUNDEX", 1, {FIELD_TYPE_STRING}, FIELD_TYPE_STRING, soundexFunc,
 	 NULL},
 	{"SUBSTR", 2, {FIELD_TYPE_STRING, FIELD_TYPE_INTEGER},
-	 FIELD_TYPE_STRING, substrFunc, NULL},
+	 FIELD_TYPE_STRING, func_substr_characters, NULL},
 	{"SUBSTR", 3,
 	 {FIELD_TYPE_STRING, FIELD_TYPE_INTEGER, FIELD_TYPE_INTEGER},
-	 FIELD_TYPE_STRING, substrFunc, NULL},
+	 FIELD_TYPE_STRING, func_substr_characters, NULL},
 	{"SUBSTR", 2, {FIELD_TYPE_VARBINARY, FIELD_TYPE_INTEGER},
-	 FIELD_TYPE_VARBINARY, substrFunc, NULL},
+	 FIELD_TYPE_VARBINARY, func_substr_octets, NULL},
 	{"SUBSTR", 3,
 	 {FIELD_TYPE_VARBINARY, FIELD_TYPE_INTEGER, FIELD_TYPE_INTEGER},
-	 FIELD_TYPE_VARBINARY, substrFunc, NULL},
+	 FIELD_TYPE_VARBINARY, func_substr_octets, NULL},
 	{"SUM", 1, {FIELD_TYPE_INTEGER}, FIELD_TYPE_INTEGER, step_sum, NULL},
 	{"SUM", 1, {FIELD_TYPE_DOUBLE}, FIELD_TYPE_DOUBLE, step_sum, NULL},
 	{"TOTAL", 1, {FIELD_TYPE_INTEGER}, FIELD_TYPE_DOUBLE, step_total,
diff --git a/test/sql-tap/func.test.lua b/test/sql-tap/func.test.lua
index 416f27d69..dc4dfdc0e 100755
--- a/test/sql-tap/func.test.lua
+++ b/test/sql-tap/func.test.lua
@@ -139,7 +139,7 @@ test:do_execsql_test(
         SELECT substr(t1,-1,1) FROM tbl1 ORDER BY t1
     ]], {
         -- <func-2.3>
-        "e", "s", "m", "e", "s"
+        "", "", "", "", ""
         -- </func-2.3>
     })
 
@@ -149,7 +149,7 @@ test:do_execsql_test(
         SELECT substr(t1,-1,2) FROM tbl1 ORDER BY t1
     ]], {
         -- <func-2.4>
-        "e", "s", "m", "e", "s"
+        "", "", "", "", ""
         -- </func-2.4>
     })
 
@@ -159,7 +159,7 @@ test:do_execsql_test(
         SELECT substr(t1,-2,1) FROM tbl1 ORDER BY t1
     ]], {
         -- <func-2.5>
-        "e", "i", "a", "r", "i"
+        "", "", "", "", ""
         -- </func-2.5>
     })
 
@@ -169,7 +169,7 @@ test:do_execsql_test(
         SELECT substr(t1,-2,2) FROM tbl1 ORDER BY t1
     ]], {
         -- <func-2.6>
-        "ee", "is", "am", "re", "is"
+        "", "", "", "", ""
         -- </func-2.6>
     })
 
@@ -179,7 +179,7 @@ test:do_execsql_test(
         SELECT substr(t1,-4,2) FROM tbl1 ORDER BY t1
     ]], {
         -- <func-2.7>
-        "fr", "", "gr", "wa", "th"
+        "", "", "", "", ""
         -- </func-2.7>
     })
 
@@ -288,7 +288,7 @@ if ("ሴ" ~= "u1234") then
             SELECT substr(t1,-1,1) FROM tbl1 ORDER BY t1
         ]], {
             -- <func-3.8>
-            "8", "s", "s", "o"
+            "", "", "", ""
             -- </func-3.8>
         })
 
@@ -298,7 +298,7 @@ if ("ሴ" ~= "u1234") then
             SELECT substr(t1,-3,2) FROM tbl1 ORDER BY t1
         ]], {
             -- <func-3.9>
-            "F-", "er", "in", "ሴh"
+            "", "", "", ""
             -- </func-3.9>
         })
 
@@ -308,7 +308,7 @@ if ("ሴ" ~= "u1234") then
             SELECT substr(t1,-4,3) FROM tbl1 ORDER BY t1
         ]], {
             -- <func-3.10>
-            "TF-", "ter", "ain", "iሴh"
+            "", "", "", ""
             -- </func-3.10>
         })
 
diff --git a/test/sql-tap/func2.test.lua b/test/sql-tap/func2.test.lua
index 792f020f1..b786b4d96 100755
--- a/test/sql-tap/func2.test.lua
+++ b/test/sql-tap/func2.test.lua
@@ -162,7 +162,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -1)
     ]], {
         -- <func2-1.11>
-        "s"
+        "Supercalifragilisticexpialidocious"
         -- </func2-1.11>
     })
 
@@ -172,7 +172,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -2)
     ]], {
         -- <func2-1.12>
-        "us"
+        "Supercalifragilisticexpialidocious"
         -- </func2-1.12>
     })
 
@@ -182,7 +182,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -30)
     ]], {
         -- <func2-1.13>
-        "rcalifragilisticexpialidocious"
+        "Supercalifragilisticexpialidocious"
         -- </func2-1.13>
     })
 
@@ -344,7 +344,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -1, 1)
     ]], {
         -- <func2-1.25.1>
-        "s"
+        ""
         -- </func2-1.25.1>
     })
 
@@ -354,7 +354,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -1, 2)
     ]], {
         -- <func2-1.25.2>
-        "s"
+        ""
         -- </func2-1.25.2>
     })
 
@@ -364,7 +364,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -2, 1)
     ]], {
         -- <func2-1.26>
-        "u"
+        ""
         -- </func2-1.26>
     })
 
@@ -374,7 +374,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -30, 1)
     ]], {
         -- <func2-1.27>
-        "r"
+        ""
         -- </func2-1.27>
     })
 
@@ -394,7 +394,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -34, 1)
     ]], {
         -- <func2-1.28.1>
-        "S"
+        ""
         -- </func2-1.28.1>
     })
 
@@ -404,7 +404,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -34, 2)
     ]], {
         -- <func2-1.28.2>
-        "Su"
+        ""
         -- </func2-1.28.2>
     })
 
@@ -424,7 +424,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -35, 2)
     ]], {
         -- <func2-1.29.2>
-        "S"
+        ""
         -- </func2-1.29.2>
     })
 
@@ -464,11 +464,13 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -36, 3)
     ]], {
         -- <func2-1.30.3>
-        "S"
+        ""
         -- </func2-1.30.3>
     })
 
 -- p1 is 1-indexed, p2 length to return, p2<0 return p2 chars before p1
+local err = [[Failed to execute SQL statement: Length of the result cannot ]]..
+            [[be less than 0]]
 test:do_execsql_test(
     "func2-1.31.0",
     [[
@@ -479,23 +481,23 @@ test:do_execsql_test(
         -- </func2-1.31.0>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.31.1",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 0, -1)
     ]], {
         -- <func2-1.31.1>
-        ""
+        1, err
         -- </func2-1.31.1>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.31.2",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 0, -2)
     ]], {
         -- <func2-1.31.2>
-        ""
+        1, err
         -- </func2-1.31.2>
     })
 
@@ -509,13 +511,13 @@ test:do_execsql_test(
         -- </func2-1.32.0>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.32.1",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 1, -1)
     ]], {
         -- <func2-1.32.1>
-        ""
+        1, err
         -- </func2-1.32.1>
     })
 
@@ -529,23 +531,23 @@ test:do_execsql_test(
         -- </func2-1.33.0>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.33.1",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 2, -1)
     ]], {
         -- <func2-1.33.1>
-        "S"
+        1, err
         -- </func2-1.33.1>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.33.2",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 2, -2)
     ]], {
         -- <func2-1.33.2>
-        "S"
+        1, err
         -- </func2-1.33.2>
     })
 
@@ -559,63 +561,63 @@ test:do_execsql_test(
         -- </func2-1.34.0>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.34.1",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 3, -1)
     ]], {
         -- <func2-1.34.1>
-        "u"
+        1, err
         -- </func2-1.34.1>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.34.2",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 3, -2)
     ]], {
         -- <func2-1.34.2>
-        "Su"
+        1, err
         -- </func2-1.34.2>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.35.1",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 30, -1)
     ]], {
         -- <func2-1.35.1>
-        "o"
+        1, err
         -- </func2-1.35.1>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.35.2",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 30, -2)
     ]], {
         -- <func2-1.35.2>
-        "do"
+        1, err
         -- </func2-1.35.2>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.36",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 34, -1)
     ]], {
         -- <func2-1.36>
-        "u"
+        1, err
         -- </func2-1.36>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.37",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 35, -1)
     ]], {
         -- <func2-1.37>
-        "s"
+        1, err
         -- </func2-1.37>
     })
 
@@ -629,23 +631,23 @@ test:do_execsql_test(
         -- </func2-1.38.0>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.38.1",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 36, -1)
     ]], {
         -- <func2-1.38.1>
-        ""
+        1, err
         -- </func2-1.38.1>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.38.2",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 36, -2)
     ]], {
         -- <func2-1.38.2>
-        "s"
+        1, err
         -- </func2-1.38.2>
     })
 
@@ -993,7 +995,7 @@ if ("ሴ" ~= "u1234")
             SELECT SUBSTR('ሴ', -1, 1)
         ]], {
             -- <func2-2.8.1>
-            "ሴ"
+            ""
             -- </func2-2.8.1>
         })
 
@@ -1003,7 +1005,7 @@ if ("ሴ" ~= "u1234")
             SELECT SUBSTR('ሴ', -1, 2)
         ]], {
             -- <func2-2.8.2>
-            "ሴ"
+            ""
             -- </func2-2.8.2>
         })
 
@@ -1130,21 +1132,21 @@ test:do_test(
     function()
         local blob = test:execsql "SELECT SUBSTR(x'1234', -1, 1)"
         return bin_to_hex(test.lindex(blob, 0))
-    end, "34")
+    end, "")
 
 test:do_test(
     "func2-3.4.2",
     function()
         local blob = test:execsql "SELECT SUBSTR(x'1234', -1, 2)"
         return bin_to_hex(test.lindex(blob, 0))
-    end, "34")
+    end, "")
 
 test:do_test(
     "func2-3.4.3",
     function()
         local blob = test:execsql "SELECT SUBSTR(x'1234', -1, 3)"
         return bin_to_hex(test.lindex(blob, 0))
-    end, "34")
+    end, "12")
 
 test:do_test(
     "func2-3.5.0",
@@ -1158,21 +1160,21 @@ test:do_test(
     function()
         local blob = test:execsql "SELECT SUBSTR(x'1234', -2, 1)"
         return bin_to_hex(test.lindex(blob, 0))
-    end, "12")
+    end, "")
 
 test:do_test(
     "func2-3.5.2",
     function()
         local blob = test:execsql "SELECT SUBSTR(x'1234', -2, 2)"
         return bin_to_hex(test.lindex(blob, 0))
-    end, "1234")
+    end, "")
 
 test:do_test(
     "func2-3.5.3",
     function()
         local blob = test:execsql "SELECT SUBSTR(x'1234', -2, 3)"
         return bin_to_hex(test.lindex(blob, 0))
-    end, "1234")
+    end, "")
 
 test:do_test(
     "func2-3.6.0",
@@ -1181,26 +1183,28 @@ test:do_test(
         return bin_to_hex(test.lindex(blob, 0))
     end, "")
 
+local err = [[Failed to execute SQL statement: Length of the result cannot ]]..
+            [[be less than 0]]
 test:do_test(
     "func2-3.6.1",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', -1, -1)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "12")
+        return test:catchsql("SELECT SUBSTR(x'1234', -1, -1)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.6.2",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', -1, -2)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "12")
+        return test:catchsql("SELECT SUBSTR(x'1234', -1, -2)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.6.3",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', -1, -3)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "12")
+        return test:catchsql("SELECT SUBSTR(x'1234', -1, -3)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.7.0",
@@ -1212,16 +1216,16 @@ test:do_test(
 test:do_test(
     "func2-3.7.1",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', -2, -1)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "")
+        return test:catchsql("SELECT SUBSTR(x'1234', -2, -1)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.7.2",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', -2, -2)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "")
+        return test:catchsql("SELECT SUBSTR(x'1234', -2, -2)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.8.0",
@@ -1233,16 +1237,16 @@ test:do_test(
 test:do_test(
     "func2-3.8.1",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', 1, -1)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "")
+        return test:catchsql("SELECT SUBSTR(x'1234', 1, -1)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.8.2",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', 1, -2)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "")
+        return test:catchsql("SELECT SUBSTR(x'1234', 1, -2)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.9.0",
@@ -1254,17 +1258,15 @@ test:do_test(
 test:do_test(
     "func2-3.9.1",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', 2, -1)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "12")
+        return test:catchsql("SELECT SUBSTR(x'1234', 2, -2)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.9.2",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', 2, -2)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "12")
-
-
+        return test:catchsql("SELECT SUBSTR(x'1234', 2, -2)")
+    end,
+        {1, err})
 
 test:finish_test()
diff --git a/test/sql-tap/substr.test.lua b/test/sql-tap/substr.test.lua
index e7e6d7aca..45aae8506 100755
--- a/test/sql-tap/substr.test.lua
+++ b/test/sql-tap/substr.test.lua
@@ -1,6 +1,6 @@
 #!/usr/bin/env tarantool
 local test = require("sqltester")
-test:plan(93)
+test:plan(85)
 
 --!./tcltestrunner.lua
 -- 2007 May 14
@@ -74,17 +74,11 @@ substr_test("1.2", "abcdefg","2","1","b")
 substr_test("1.3", "abcdefg","1","2","ab")
 substr_test("1.4", "abcdefg","1","100","abcdefg")
 substr_test("1.5", "abcdefg","0","2","a")
-substr_test("1.6", "abcdefg","-1","1","g")
-substr_test("1.7", "abcdefg","-1","10","g")
-substr_test("1.8", "abcdefg","-5","3","cde")
-substr_test("1.9", "abcdefg","-7","3","abc")
-substr_test("1.10", "abcdefg","-100","98","abcde")
-substr_test("1.11", "abcdefg","5","-1","d")
-substr_test("1.12", "abcdefg","5","-4","abcd")
-substr_test("1.13", "abcdefg","5","-5","abcd")
-substr_test("1.14", "abcdefg","-5","-1","b")
-substr_test("1.15", "abcdefg","-5","-2","ab")
-substr_test("1.16", "abcdefg","-5","-3","ab")
+substr_test("1.6", "abcdefg","-1","1","")
+substr_test("1.7", "abcdefg","-1","10","abcdefg")
+substr_test("1.8", "abcdefg","-5","3","")
+substr_test("1.9", "abcdefg","-7","3","")
+substr_test("1.10", "abcdefg","-100","98","")
 substr_test("1.17", "abcdefg","100","200","")
 substr_test("1.18", "abcdefg","200","100","")
 -- Make sure NULL is returned if any parameter is NULL
@@ -144,21 +138,20 @@ test:do_test(
 substr_test("2.1", "ሴ⍅㑖","1","1","ሴ")
 substr_test("2.2", "ሴ⍅㑖","2","1","⍅")
 substr_test("2.3", "ሴ⍅㑖","1","2","ሴ⍅")
-substr_test("2.4", "ሴ⍅㑖","-1","1","㑖")
-substr_test("2.5", "aሴb⍅c㑖c","-5","3","b⍅c")
-substr_test("2.6", "aሴb⍅c㑖c","-2","-3","b⍅c")
+substr_test("2.4", "ሴ⍅㑖","-1","1","")
+substr_test("2.5", "aሴb⍅c㑖c","-5","3","")
 -- Basic functionality for BLOBs
 --
 subblob_test("3.1", "61626364656667","1","1","61")
 subblob_test("3.2", "61626364656667","2","1","62")
 subblob_test("3.3", "61626364656667","1","2","6162")
 subblob_test("3.4", "61626364656667","1","100","61626364656667")
-subblob_test("3.5", "61626364656667","0","2","61")
-subblob_test("3.6", "61626364656667","-1","1","67")
-subblob_test("3.7", "61626364656667","-1","10","67")
-subblob_test("3.8", "61626364656667","-5","3","636465")
-subblob_test("3.9", "61626364656667","-7","3","616263")
-subblob_test("3.10", "61626364656667","-100","98","6162636465")
+subblob_test("3.5", "61626364656667", "0", "2", "61")
+subblob_test("3.6", "61626364656667", "-1", "1", "")
+subblob_test("3.7", "61626364656667", "-1", "10", "61626364656667")
+subblob_test("3.8", "61626364656667", "-5", "3", "")
+subblob_test("3.9", "61626364656667","-7","3", "")
+subblob_test("3.10", "61626364656667", "-100", "98", "")
 subblob_test("3.11", "61626364656667","100","200","")
 subblob_test("3.12", "61626364656667","200","100","")
 -- If these blobs were strings, then they would contain multi-byte
@@ -168,9 +161,9 @@ subblob_test("3.12", "61626364656667","200","100","")
 subblob_test("4.1", "61E188B462E28D8563E3919663","1","1","61")
 subblob_test("4.2", "61E188B462E28D8563E3919663","2","1","E1")
 subblob_test("4.3", "61E188B462E28D8563E3919663","1","2","61E1")
-subblob_test("4.4", "61E188B462E28D8563E3919663","-2","1","96")
-subblob_test("4.5", "61E188B462E28D8563E3919663","-5","4","63E39196")
-subblob_test("4.6", "61E188B462E28D8563E3919663","-100","98","61E188B462E28D8563E391")
+subblob_test("4.4", "61E188B462E28D8563E3919663", "-2", "1", "")
+subblob_test("4.5", "61E188B462E28D8563E3919663", "-5", "4", "")
+subblob_test("4.6", "61E188B462E28D8563E3919663", "-100", "98", "")
 -- Two-argument SUBSTR
 --
 local function substr_2_test(id, string, idx, result)
@@ -193,7 +186,85 @@ local function substr_2_test(id, string, idx, result)
 end
 
 substr_2_test("5.1","abcdefghijklmnop","5","efghijklmnop")
-substr_2_test("5.2","abcdef","-5","bcdef")
+substr_2_test("5.2","abcdef","-5","abcdef")
 
+--
+-- gh-4145: Make sure SUBSTR() throws an error if the third argument is
+-- negative.
+--
+test:do_catchsql_test(
+    "substr-6.1",
+    [[
+        SELECT SUBSTR('12345', 1, -1);
+    ]],
+    {
+        1, [[Failed to execute SQL statement: ]]..
+           [[Length of the result cannot be less than 0]]
+    }
+)
+
+test:do_catchsql_test(
+    "substr-6.2",
+    [[
+        SELECT SUBSTR(x'3132333435', 1, -1);
+    ]],
+    {
+        1, [[Failed to execute SQL statement: ]]..
+           [[Length of the result cannot be less than 0]]
+    }
+)
+
+-- gh-4145: Make sure that SUBSTR() works according to ANSI.
+
+--
+-- Make sure SUBSTR() returns "" if the sum of the second and third arguments is
+-- 1 or less.
+--
+test:do_execsql_test(
+    "builtins-6.3",
+    [[
+        SELECT SUBSTR('asdfg', -10, 5), SUBSTR('asdfg', -4, 5);
+    ]],
+    {
+        '', ''
+    }
+)
+
+--
+-- Make sure that if the sum of the second and third arguments is more than 1
+-- and the second argument is negative, the result starts from the start of the
+-- string and length of the result will be one less than sum of the  second and
+-- third arguments.
+--
+test:do_execsql_test(
+    "builtins-6.4",
+    [[
+        SELECT SUBSTR('123456789', -5, 10);
+    ]],
+    {
+        '1234'
+    }
+)
+
+-- Make sure SUBSTR() can work with big INTEGERs.
+test:do_execsql_test(
+    "builtins-6.5",
+    [[
+        SELECT SUBSTR('123456789', -9223372036854775808, 9223372036854775812);
+    ]],
+    {
+        '123'
+    }
+)
+
+test:do_execsql_test(
+    "builtins-6.6",
+    [[
+        SELECT SUBSTR('123456789', 0, 18000000000000000000);
+    ]],
+    {
+        '123456789'
+    }
+)
 
 test:finish_test()

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [Tarantool-patches] [PATCH v1 7/8] sql: rework SUBSTR() function
  2021-10-20 17:15     ` Mergen Imeev via Tarantool-patches
@ 2021-10-28 22:13       ` Vladislav Shpilevoy via Tarantool-patches
  2021-11-01 10:45         ` Mergen Imeev via Tarantool-patches
  0 siblings, 1 reply; 15+ messages in thread
From: Vladislav Shpilevoy via Tarantool-patches @ 2021-10-28 22:13 UTC (permalink / raw)
  To: Mergen Imeev; +Cc: tarantool-patches

Thanks for the fixes!

> diff --git a/src/box/sql/func.c b/src/box/sql/func.c
> index 80b075dcf..65bf03250 100644
> --- a/src/box/sql/func.c
> +++ b/src/box/sql/func.c
> +
> +static void
> +func_substr_octets(struct sql_context *ctx, int argc, struct Mem *argv)
> +{
> +	assert(argc == 2 || argc == 3);
> +	if (mem_is_any_null(&argv[0], &argv[1]))
> +		return;
> +	assert(mem_is_bytes(&argv[0]) && mem_is_int(&argv[1]));
> +
> +	bool is_str = mem_is_str(&argv[0]);
> +	uint64_t size = argv[0].n;
> +
> +	if (argc == 2) {
> +		uint64_t start = mem_is_uint(&argv[1]) && argv[1].u.u > 1 ?
> +				 argv[1].u.u - 1 : 0;
> +		if (start >= size)
> +			return return_empty_str(ctx, is_str);
> +		char *s = &argv[0].z[start];
> +		uint64_t n = size - start;
> +		ctx->is_aborted = is_str ? mem_copy_str(ctx->pOut, s, n) != 0 :
> +				  mem_copy_bin(ctx->pOut, s, n) != 0;
> +		return;
> +	}
> +
> +	assert(argc == 3);
> +	if (mem_is_null(&argv[2]))
> +		return;
> +	assert(mem_is_int(&argv[2]));
> +	if (!mem_is_uint(&argv[2])) {
> +		diag_set(ClientError, ER_SQL_EXECUTE, "Length of the result "
> +			 "cannot be less than 0");
> +		ctx->is_aborted = true;
> +		return;
> +	}
> +	uint64_t start;
> +	uint64_t length;
> +	if (substr_normalize(argv[1].u.i, !mem_is_uint(&argv[1]), argv[2].u.u,
> +	    &start, &length) != 0) {

The second line of the call is misaligned.

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [Tarantool-patches] [PATCH v1 7/8] sql: rework SUBSTR() function
  2021-10-08 22:02   ` Vladislav Shpilevoy via Tarantool-patches
@ 2021-10-20 17:15     ` Mergen Imeev via Tarantool-patches
  2021-10-28 22:13       ` Vladislav Shpilevoy via Tarantool-patches
  0 siblings, 1 reply; 15+ messages in thread
From: Mergen Imeev via Tarantool-patches @ 2021-10-20 17:15 UTC (permalink / raw)
  To: Vladislav Shpilevoy; +Cc: tarantool-patches

Thank you for review! My answers, diff and new patch below. Also, I replaced
self-created functions ucnv_getNextUChar().

On Sat, Oct 09, 2021 at 12:02:14AM +0200, Vladislav Shpilevoy wrote:
> Thanks for the patch!
> 
> On 01.10.2021 18:29, Mergen Imeev via Tarantool-patches wrote:
> > This patch makes SUBSTR() work according to ANSI rules for SUBSTRING()
> > function. Also, SUBSTR() can now work correctly with large INTEGER
> > values. The SUBSTR() syntax has not changed.
> 
> Does not make much sense given that Mem.n is just int. You can't
> have strings or blobs larger than that.
> 
> > Part of #4145
> > 
> > @TarantoolBot document
> > Title: SUBSTR() function
> > 
> > SUBSTR() now works according to the ANSI rules for SUBSTRING(), but with
> > no syntax changes. What changed:
> > 1) if the third argument is specified and it is less than 0, an error is
> > thrown;
> > 2) if the sum of the second and third arguments is less than 1, an empty
> > string is returned;
> > 3) if the second argument is less than 0, and the sum of the second and
> > third arguments is greater than 1, then the result is equal to the
> > result of SUBSTR() with the second argument equal to 1 and the third
> > argument equal to the sum of the original second and third arguments
> > minus 1.
> 
> I don't understand how it works now. What are the arguments? What
> do they do? Can you explain fully? I see that a lot of tests now has
> turned into errors and I don't understand why did they stop working.
> 
> In the code I couldn't find any comments.
Rewrote the docbot request. I thought about adding comments, but maybe it's
better to divide these two functions into four? One for two VARBINARY
arguments, one for three VARBINARY arguments, and the same for STRING
arguments.


Diff:

diff --git a/src/box/sql/func.c b/src/box/sql/func.c
index 441fab482..65bf03250 100644
--- a/src/box/sql/func.c
+++ b/src/box/sql/func.c
@@ -670,20 +670,17 @@ func_substr_characters(struct sql_context *ctx, int argc, struct Mem *argv)
 		return;
 	assert(mem_is_str(&argv[0]) && mem_is_int(&argv[1]));
 
-	uint64_t size = argv[0].n;
-
+	UErrorCode err = U_ZERO_ERROR;
+	const char *pos = argv[0].z;
+	const char *end = argv[0].z + argv[0].n;
 	if (argc == 2) {
 		uint64_t start = mem_is_uint(&argv[1]) && argv[1].u.u > 1 ?
 				 argv[1].u.u - 1 : 0;
-		char *str = argv[0].z;
-		uint64_t s = 0;
-		for (uint64_t i = 0; i < start && s < size; ++i)
-			s += utf8_len_char(str[s]);
-
-		if (s >= size)
+		for (uint64_t i = 0; i < start && pos < end; ++i)
+			ucnv_getNextUChar(icu_utf8_conv, &pos, end, &err);
+		if (pos == end)
 			return mem_set_str_static(ctx->pOut, "", 0);
-		uint64_t len = size - s;
-		if (mem_copy_str(ctx->pOut, &str[s], len) != 0)
+		if (mem_copy_str(ctx->pOut, pos, end - pos) != 0)
 			ctx->is_aborted = true;
 		return;
 	}
@@ -708,18 +705,15 @@ func_substr_characters(struct sql_context *ctx, int argc, struct Mem *argv)
 	if (length == 0)
 		return mem_set_str_static(ctx->pOut, "", 0);
 
-	char *str = argv[0].z;
-	uint64_t s = 0;
-	for (uint64_t i = 0; i < start && s < size; ++i)
-		s += utf8_len_char(str[s]);
-	uint64_t e = s;
-	for (uint64_t i = 0; i < length && e < size; ++i)
-		e += utf8_len_char(str[e]);
-	if (s >= size)
+	for (uint64_t i = 0; i < start && err == U_ZERO_ERROR; ++i)
+		ucnv_getNextUChar(icu_utf8_conv, &pos, end, &err);
+	const char *cur = pos;
+	for (uint64_t i = 0; i < length && cur < end; ++i)
+		ucnv_getNextUChar(icu_utf8_conv, &cur, end, &err);
+	if (err != U_ZERO_ERROR || cur == pos)
 		return mem_set_str_static(ctx->pOut, "", 0);
 
-	uint64_t len = MIN(e, size) - s;
-	if (mem_copy_str(ctx->pOut, &str[s], len) != 0)
+	if (mem_copy_str(ctx->pOut, pos, cur - pos) != 0)
 		ctx->is_aborted = true;
 }
 

New patch:

commit 8bf344a18cac835818142a9c76f327136ce29903
Author: Mergen Imeev <imeevma@gmail.com>
Date:   Mon Sep 27 10:15:14 2021 +0300

    sql: rework SUBSTR() function
    
    This patch makes SUBSTR() work according to ANSI rules for SUBSTRING()
    function. Also, SUBSTR() can now work correctly with large INTEGER
    values. The SUBSTR() syntax has not changed.
    
    Part of #4145
    
    @TarantoolBot document
    Title: SUBSTR() function
    
    SUBSTR() now works according to the ANSI rules for SUBSTRING().
    
    Rules for SUBSTR() with 2 arguments:
    1) let the first argument be VALUE, and the second argument be START;
    2) VALUE should be STRING or VARBINARY, START should be INTEGER;
    3) if any of arguments is NULL, NULL is returned;
    4) let POS be MAX(START - 1, 0), END be length of the VALUE;
    5) if POS >= END, the result is empty string;
    6) if POS < END, the result will be substring of VALUE, starting from
       the position POS to the position END.
    
    Rules for SUBSTR() with 3 arguments:
    1) let the first argument be VALUE, the second argument be START, and
       the third argument be LENGTH;
    2) VALUE should be STRING or VARBINARY, START and LENGTH should be
       INTEGERs;
    3) if any of arguments is NULL, NULL is returned;
    4) if LENGTH < 0, an error is thrown;
    5) let POS be MAX(START - 1, 0), END be START + LENGTH - 1;
    6) if POS >= END, the result is empty string;
    7) if POS < END, the result will be substring of VALUE, starting from
       the position POS to the position END.

diff --git a/src/box/sql/func.c b/src/box/sql/func.c
index 80b075dcf..65bf03250 100644
--- a/src/box/sql/func.c
+++ b/src/box/sql/func.c
@@ -577,6 +577,146 @@ func_position_characters(struct sql_context *ctx, int argc, struct Mem *argv)
 	return mem_set_uint(ctx->pOut, 0);
 }
 
+/** Implementation of the SUBSTR() function. */
+int
+substr_normalize(int64_t base_start, bool is_start_neg, uint64_t base_length,
+		 uint64_t *start, uint64_t *length)
+{
+	if (!is_start_neg && base_start > 0) {
+		*start = (uint64_t)base_start - 1;
+		*length = base_length;
+		return 0;
+	}
+	*start = 0;
+	if (base_length == 0) {
+		*length = 0;
+		return 0;
+	}
+	/*
+	 * We are subtracting 1 from base_length instead of subtracting from
+	 * base_start, since base_start can be INT64_MIN. At the same time,
+	 * base_length is not less than 1.
+	 */
+	int64_t a = base_start;
+	int64_t b = (int64_t)(base_length - 1);
+	int64_t res;
+	bool is_neg;
+	/*
+	 * Integer cannot overflow since non-positive value is added to positive
+	 * value.
+	 */
+	if (sql_add_int(a, a != 0, b, false, &res, &is_neg) != 0) {
+		diag_set(ClientError, ER_SQL_EXECUTE, "integer is overflowed");
+		return -1;
+	}
+	*length = is_neg ? 0 : (uint64_t)res;
+	return 0;
+}
+
+static void
+func_substr_octets(struct sql_context *ctx, int argc, struct Mem *argv)
+{
+	assert(argc == 2 || argc == 3);
+	if (mem_is_any_null(&argv[0], &argv[1]))
+		return;
+	assert(mem_is_bytes(&argv[0]) && mem_is_int(&argv[1]));
+
+	bool is_str = mem_is_str(&argv[0]);
+	uint64_t size = argv[0].n;
+
+	if (argc == 2) {
+		uint64_t start = mem_is_uint(&argv[1]) && argv[1].u.u > 1 ?
+				 argv[1].u.u - 1 : 0;
+		if (start >= size)
+			return return_empty_str(ctx, is_str);
+		char *s = &argv[0].z[start];
+		uint64_t n = size - start;
+		ctx->is_aborted = is_str ? mem_copy_str(ctx->pOut, s, n) != 0 :
+				  mem_copy_bin(ctx->pOut, s, n) != 0;
+		return;
+	}
+
+	assert(argc == 3);
+	if (mem_is_null(&argv[2]))
+		return;
+	assert(mem_is_int(&argv[2]));
+	if (!mem_is_uint(&argv[2])) {
+		diag_set(ClientError, ER_SQL_EXECUTE, "Length of the result "
+			 "cannot be less than 0");
+		ctx->is_aborted = true;
+		return;
+	}
+	uint64_t start;
+	uint64_t length;
+	if (substr_normalize(argv[1].u.i, !mem_is_uint(&argv[1]), argv[2].u.u,
+	    &start, &length) != 0) {
+		ctx->is_aborted = true;
+		return;
+	}
+	if (start >= size || length == 0)
+		return return_empty_str(ctx, is_str);
+	char *str = &argv[0].z[start];
+	uint64_t len = MIN(size - start, length);
+	ctx->is_aborted = is_str ? mem_copy_str(ctx->pOut, str, len) != 0 :
+			  mem_copy_bin(ctx->pOut, str, len) != 0;
+}
+
+static void
+func_substr_characters(struct sql_context *ctx, int argc, struct Mem *argv)
+{
+	assert(argc == 2 || argc == 3);
+	(void)argc;
+	if (mem_is_any_null(&argv[0], &argv[1]))
+		return;
+	assert(mem_is_str(&argv[0]) && mem_is_int(&argv[1]));
+
+	UErrorCode err = U_ZERO_ERROR;
+	const char *pos = argv[0].z;
+	const char *end = argv[0].z + argv[0].n;
+	if (argc == 2) {
+		uint64_t start = mem_is_uint(&argv[1]) && argv[1].u.u > 1 ?
+				 argv[1].u.u - 1 : 0;
+		for (uint64_t i = 0; i < start && pos < end; ++i)
+			ucnv_getNextUChar(icu_utf8_conv, &pos, end, &err);
+		if (pos == end)
+			return mem_set_str_static(ctx->pOut, "", 0);
+		if (mem_copy_str(ctx->pOut, pos, end - pos) != 0)
+			ctx->is_aborted = true;
+		return;
+	}
+
+	assert(argc == 3);
+	if (mem_is_null(&argv[2]))
+		return;
+	assert(mem_is_int(&argv[2]));
+	if (!mem_is_uint(&argv[2])) {
+		diag_set(ClientError, ER_SQL_EXECUTE, "Length of the result "
+			 "cannot be less than 0");
+		ctx->is_aborted = true;
+		return;
+	}
+	uint64_t start;
+	uint64_t length;
+	if (substr_normalize(argv[1].u.i, !mem_is_uint(&argv[1]), argv[2].u.u,
+	    &start, &length) != 0) {
+		ctx->is_aborted = true;
+		return;
+	}
+	if (length == 0)
+		return mem_set_str_static(ctx->pOut, "", 0);
+
+	for (uint64_t i = 0; i < start && err == U_ZERO_ERROR; ++i)
+		ucnv_getNextUChar(icu_utf8_conv, &pos, end, &err);
+	const char *cur = pos;
+	for (uint64_t i = 0; i < length && cur < end; ++i)
+		ucnv_getNextUChar(icu_utf8_conv, &cur, end, &err);
+	if (err != U_ZERO_ERROR || cur == pos)
+		return mem_set_str_static(ctx->pOut, "", 0);
+
+	if (mem_copy_str(ctx->pOut, pos, cur - pos) != 0)
+		ctx->is_aborted = true;
+}
+
 static const unsigned char *
 mem_as_ustr(struct Mem *mem)
 {
@@ -774,116 +914,6 @@ printfFunc(struct sql_context *context, int argc, struct Mem *argv)
 	}
 }
 
-/*
- * Implementation of the substr() function.
- *
- * substr(x,p1,p2)  returns p2 characters of x[] beginning with p1.
- * p1 is 1-indexed.  So substr(x,1,1) returns the first character
- * of x.  If x is text, then we actually count UTF-8 characters.
- * If x is a blob, then we count bytes.
- *
- * If p1 is negative, then we begin abs(p1) from the end of x[].
- *
- * If p2 is negative, return the p2 characters preceding p1.
- */
-static void
-substrFunc(struct sql_context *context, int argc, struct Mem *argv)
-{
-	const unsigned char *z;
-	const unsigned char *z2;
-	int len;
-	int p0type;
-	int64_t p1, p2;
-	int negP2 = 0;
-
-	if (argc != 2 && argc != 3) {
-		diag_set(ClientError, ER_FUNC_WRONG_ARG_COUNT, "SUBSTR",
-			 "1 or 2", argc);
-		context->is_aborted = true;
-		return;
-	}
-	if (mem_is_null(&argv[1]) || (argc == 3 && mem_is_null(&argv[2])))
-		return;
-	p0type = sql_value_type(&argv[0]);
-	p1 = mem_get_int_unsafe(&argv[1]);
-	if (p0type == MP_BIN) {
-		z = mem_as_bin(&argv[0]);
-		len = mem_len_unsafe(&argv[0]);
-		if (z == 0)
-			return;
-		assert(len == mem_len_unsafe(&argv[0]));
-	} else {
-		z = mem_as_ustr(&argv[0]);
-		if (z == 0)
-			return;
-		len = 0;
-		if (p1 < 0)
-			len = sql_utf8_char_count(z, mem_len_unsafe(&argv[0]));
-	}
-	if (argc == 3) {
-		p2 = mem_get_int_unsafe(&argv[2]);
-		if (p2 < 0) {
-			p2 = -p2;
-			negP2 = 1;
-		}
-	} else {
-		p2 = sql_context_db_handle(context)->
-		    aLimit[SQL_LIMIT_LENGTH];
-	}
-	if (p1 < 0) {
-		p1 += len;
-		if (p1 < 0) {
-			p2 += p1;
-			if (p2 < 0)
-				p2 = 0;
-			p1 = 0;
-		}
-	} else if (p1 > 0) {
-		p1--;
-	} else if (p2 > 0) {
-		p2--;
-	}
-	if (negP2) {
-		p1 -= p2;
-		if (p1 < 0) {
-			p2 += p1;
-			p1 = 0;
-		}
-	}
-	assert(p1 >= 0 && p2 >= 0);
-	if (p0type != MP_BIN) {
-		/*
-		 * In the code below 'cnt' and 'n_chars' is
-		 * used because '\0' is not supposed to be
-		 * end-of-string symbol.
-		 */
-		int byte_size = mem_len_unsafe(&argv[0]);
-		int n_chars = sql_utf8_char_count(z, byte_size);
-		int cnt = 0;
-		int i = 0;
-		while (cnt < n_chars && p1) {
-			SQL_UTF8_FWD_1(z, i, byte_size);
-			cnt++;
-			p1--;
-		}
-		z += i;
-		i = 0;
-		for (z2 = z; cnt < n_chars && p2; p2--) {
-			SQL_UTF8_FWD_1(z2, i, byte_size);
-			cnt++;
-		}
-		z2 += i;
-		mem_copy_str(context->pOut, (char *)z, z2 - z);
-	} else {
-		if (p1 + p2 > len) {
-			p2 = len - p1;
-			if (p2 < 0)
-				p2 = 0;
-		}
-		mem_copy_bin(context->pOut, (char *)&z[p1], p2);
-	}
-}
-
 /*
  * Implementation of the round() function
  */
@@ -1937,15 +1967,15 @@ static struct sql_func_definition definitions[] = {
 	{"SOUNDEX", 1, {FIELD_TYPE_STRING}, FIELD_TYPE_STRING, soundexFunc,
 	 NULL},
 	{"SUBSTR", 2, {FIELD_TYPE_STRING, FIELD_TYPE_INTEGER},
-	 FIELD_TYPE_STRING, substrFunc, NULL},
+	 FIELD_TYPE_STRING, func_substr_characters, NULL},
 	{"SUBSTR", 3,
 	 {FIELD_TYPE_STRING, FIELD_TYPE_INTEGER, FIELD_TYPE_INTEGER},
-	 FIELD_TYPE_STRING, substrFunc, NULL},
+	 FIELD_TYPE_STRING, func_substr_characters, NULL},
 	{"SUBSTR", 2, {FIELD_TYPE_VARBINARY, FIELD_TYPE_INTEGER},
-	 FIELD_TYPE_VARBINARY, substrFunc, NULL},
+	 FIELD_TYPE_VARBINARY, func_substr_octets, NULL},
 	{"SUBSTR", 3,
 	 {FIELD_TYPE_VARBINARY, FIELD_TYPE_INTEGER, FIELD_TYPE_INTEGER},
-	 FIELD_TYPE_VARBINARY, substrFunc, NULL},
+	 FIELD_TYPE_VARBINARY, func_substr_octets, NULL},
 	{"SUM", 1, {FIELD_TYPE_INTEGER}, FIELD_TYPE_INTEGER, step_sum, NULL},
 	{"SUM", 1, {FIELD_TYPE_DOUBLE}, FIELD_TYPE_DOUBLE, step_sum, NULL},
 	{"TOTAL", 1, {FIELD_TYPE_INTEGER}, FIELD_TYPE_DOUBLE, step_total,
diff --git a/test/sql-tap/func.test.lua b/test/sql-tap/func.test.lua
index 416f27d69..dc4dfdc0e 100755
--- a/test/sql-tap/func.test.lua
+++ b/test/sql-tap/func.test.lua
@@ -139,7 +139,7 @@ test:do_execsql_test(
         SELECT substr(t1,-1,1) FROM tbl1 ORDER BY t1
     ]], {
         -- <func-2.3>
-        "e", "s", "m", "e", "s"
+        "", "", "", "", ""
         -- </func-2.3>
     })
 
@@ -149,7 +149,7 @@ test:do_execsql_test(
         SELECT substr(t1,-1,2) FROM tbl1 ORDER BY t1
     ]], {
         -- <func-2.4>
-        "e", "s", "m", "e", "s"
+        "", "", "", "", ""
         -- </func-2.4>
     })
 
@@ -159,7 +159,7 @@ test:do_execsql_test(
         SELECT substr(t1,-2,1) FROM tbl1 ORDER BY t1
     ]], {
         -- <func-2.5>
-        "e", "i", "a", "r", "i"
+        "", "", "", "", ""
         -- </func-2.5>
     })
 
@@ -169,7 +169,7 @@ test:do_execsql_test(
         SELECT substr(t1,-2,2) FROM tbl1 ORDER BY t1
     ]], {
         -- <func-2.6>
-        "ee", "is", "am", "re", "is"
+        "", "", "", "", ""
         -- </func-2.6>
     })
 
@@ -179,7 +179,7 @@ test:do_execsql_test(
         SELECT substr(t1,-4,2) FROM tbl1 ORDER BY t1
     ]], {
         -- <func-2.7>
-        "fr", "", "gr", "wa", "th"
+        "", "", "", "", ""
         -- </func-2.7>
     })
 
@@ -288,7 +288,7 @@ if ("ሴ" ~= "u1234") then
             SELECT substr(t1,-1,1) FROM tbl1 ORDER BY t1
         ]], {
             -- <func-3.8>
-            "8", "s", "s", "o"
+            "", "", "", ""
             -- </func-3.8>
         })
 
@@ -298,7 +298,7 @@ if ("ሴ" ~= "u1234") then
             SELECT substr(t1,-3,2) FROM tbl1 ORDER BY t1
         ]], {
             -- <func-3.9>
-            "F-", "er", "in", "ሴh"
+            "", "", "", ""
             -- </func-3.9>
         })
 
@@ -308,7 +308,7 @@ if ("ሴ" ~= "u1234") then
             SELECT substr(t1,-4,3) FROM tbl1 ORDER BY t1
         ]], {
             -- <func-3.10>
-            "TF-", "ter", "ain", "iሴh"
+            "", "", "", ""
             -- </func-3.10>
         })
 
diff --git a/test/sql-tap/func2.test.lua b/test/sql-tap/func2.test.lua
index 792f020f1..b786b4d96 100755
--- a/test/sql-tap/func2.test.lua
+++ b/test/sql-tap/func2.test.lua
@@ -162,7 +162,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -1)
     ]], {
         -- <func2-1.11>
-        "s"
+        "Supercalifragilisticexpialidocious"
         -- </func2-1.11>
     })
 
@@ -172,7 +172,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -2)
     ]], {
         -- <func2-1.12>
-        "us"
+        "Supercalifragilisticexpialidocious"
         -- </func2-1.12>
     })
 
@@ -182,7 +182,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -30)
     ]], {
         -- <func2-1.13>
-        "rcalifragilisticexpialidocious"
+        "Supercalifragilisticexpialidocious"
         -- </func2-1.13>
     })
 
@@ -344,7 +344,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -1, 1)
     ]], {
         -- <func2-1.25.1>
-        "s"
+        ""
         -- </func2-1.25.1>
     })
 
@@ -354,7 +354,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -1, 2)
     ]], {
         -- <func2-1.25.2>
-        "s"
+        ""
         -- </func2-1.25.2>
     })
 
@@ -364,7 +364,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -2, 1)
     ]], {
         -- <func2-1.26>
-        "u"
+        ""
         -- </func2-1.26>
     })
 
@@ -374,7 +374,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -30, 1)
     ]], {
         -- <func2-1.27>
-        "r"
+        ""
         -- </func2-1.27>
     })
 
@@ -394,7 +394,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -34, 1)
     ]], {
         -- <func2-1.28.1>
-        "S"
+        ""
         -- </func2-1.28.1>
     })
 
@@ -404,7 +404,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -34, 2)
     ]], {
         -- <func2-1.28.2>
-        "Su"
+        ""
         -- </func2-1.28.2>
     })
 
@@ -424,7 +424,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -35, 2)
     ]], {
         -- <func2-1.29.2>
-        "S"
+        ""
         -- </func2-1.29.2>
     })
 
@@ -464,11 +464,13 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -36, 3)
     ]], {
         -- <func2-1.30.3>
-        "S"
+        ""
         -- </func2-1.30.3>
     })
 
 -- p1 is 1-indexed, p2 length to return, p2<0 return p2 chars before p1
+local err = [[Failed to execute SQL statement: Length of the result cannot ]]..
+            [[be less than 0]]
 test:do_execsql_test(
     "func2-1.31.0",
     [[
@@ -479,23 +481,23 @@ test:do_execsql_test(
         -- </func2-1.31.0>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.31.1",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 0, -1)
     ]], {
         -- <func2-1.31.1>
-        ""
+        1, err
         -- </func2-1.31.1>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.31.2",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 0, -2)
     ]], {
         -- <func2-1.31.2>
-        ""
+        1, err
         -- </func2-1.31.2>
     })
 
@@ -509,13 +511,13 @@ test:do_execsql_test(
         -- </func2-1.32.0>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.32.1",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 1, -1)
     ]], {
         -- <func2-1.32.1>
-        ""
+        1, err
         -- </func2-1.32.1>
     })
 
@@ -529,23 +531,23 @@ test:do_execsql_test(
         -- </func2-1.33.0>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.33.1",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 2, -1)
     ]], {
         -- <func2-1.33.1>
-        "S"
+        1, err
         -- </func2-1.33.1>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.33.2",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 2, -2)
     ]], {
         -- <func2-1.33.2>
-        "S"
+        1, err
         -- </func2-1.33.2>
     })
 
@@ -559,63 +561,63 @@ test:do_execsql_test(
         -- </func2-1.34.0>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.34.1",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 3, -1)
     ]], {
         -- <func2-1.34.1>
-        "u"
+        1, err
         -- </func2-1.34.1>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.34.2",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 3, -2)
     ]], {
         -- <func2-1.34.2>
-        "Su"
+        1, err
         -- </func2-1.34.2>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.35.1",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 30, -1)
     ]], {
         -- <func2-1.35.1>
-        "o"
+        1, err
         -- </func2-1.35.1>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.35.2",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 30, -2)
     ]], {
         -- <func2-1.35.2>
-        "do"
+        1, err
         -- </func2-1.35.2>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.36",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 34, -1)
     ]], {
         -- <func2-1.36>
-        "u"
+        1, err
         -- </func2-1.36>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.37",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 35, -1)
     ]], {
         -- <func2-1.37>
-        "s"
+        1, err
         -- </func2-1.37>
     })
 
@@ -629,23 +631,23 @@ test:do_execsql_test(
         -- </func2-1.38.0>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.38.1",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 36, -1)
     ]], {
         -- <func2-1.38.1>
-        ""
+        1, err
         -- </func2-1.38.1>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.38.2",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 36, -2)
     ]], {
         -- <func2-1.38.2>
-        "s"
+        1, err
         -- </func2-1.38.2>
     })
 
@@ -993,7 +995,7 @@ if ("ሴ" ~= "u1234")
             SELECT SUBSTR('ሴ', -1, 1)
         ]], {
             -- <func2-2.8.1>
-            "ሴ"
+            ""
             -- </func2-2.8.1>
         })
 
@@ -1003,7 +1005,7 @@ if ("ሴ" ~= "u1234")
             SELECT SUBSTR('ሴ', -1, 2)
         ]], {
             -- <func2-2.8.2>
-            "ሴ"
+            ""
             -- </func2-2.8.2>
         })
 
@@ -1130,21 +1132,21 @@ test:do_test(
     function()
         local blob = test:execsql "SELECT SUBSTR(x'1234', -1, 1)"
         return bin_to_hex(test.lindex(blob, 0))
-    end, "34")
+    end, "")
 
 test:do_test(
     "func2-3.4.2",
     function()
         local blob = test:execsql "SELECT SUBSTR(x'1234', -1, 2)"
         return bin_to_hex(test.lindex(blob, 0))
-    end, "34")
+    end, "")
 
 test:do_test(
     "func2-3.4.3",
     function()
         local blob = test:execsql "SELECT SUBSTR(x'1234', -1, 3)"
         return bin_to_hex(test.lindex(blob, 0))
-    end, "34")
+    end, "12")
 
 test:do_test(
     "func2-3.5.0",
@@ -1158,21 +1160,21 @@ test:do_test(
     function()
         local blob = test:execsql "SELECT SUBSTR(x'1234', -2, 1)"
         return bin_to_hex(test.lindex(blob, 0))
-    end, "12")
+    end, "")
 
 test:do_test(
     "func2-3.5.2",
     function()
         local blob = test:execsql "SELECT SUBSTR(x'1234', -2, 2)"
         return bin_to_hex(test.lindex(blob, 0))
-    end, "1234")
+    end, "")
 
 test:do_test(
     "func2-3.5.3",
     function()
         local blob = test:execsql "SELECT SUBSTR(x'1234', -2, 3)"
         return bin_to_hex(test.lindex(blob, 0))
-    end, "1234")
+    end, "")
 
 test:do_test(
     "func2-3.6.0",
@@ -1181,26 +1183,28 @@ test:do_test(
         return bin_to_hex(test.lindex(blob, 0))
     end, "")
 
+local err = [[Failed to execute SQL statement: Length of the result cannot ]]..
+            [[be less than 0]]
 test:do_test(
     "func2-3.6.1",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', -1, -1)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "12")
+        return test:catchsql("SELECT SUBSTR(x'1234', -1, -1)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.6.2",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', -1, -2)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "12")
+        return test:catchsql("SELECT SUBSTR(x'1234', -1, -2)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.6.3",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', -1, -3)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "12")
+        return test:catchsql("SELECT SUBSTR(x'1234', -1, -3)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.7.0",
@@ -1212,16 +1216,16 @@ test:do_test(
 test:do_test(
     "func2-3.7.1",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', -2, -1)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "")
+        return test:catchsql("SELECT SUBSTR(x'1234', -2, -1)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.7.2",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', -2, -2)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "")
+        return test:catchsql("SELECT SUBSTR(x'1234', -2, -2)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.8.0",
@@ -1233,16 +1237,16 @@ test:do_test(
 test:do_test(
     "func2-3.8.1",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', 1, -1)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "")
+        return test:catchsql("SELECT SUBSTR(x'1234', 1, -1)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.8.2",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', 1, -2)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "")
+        return test:catchsql("SELECT SUBSTR(x'1234', 1, -2)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.9.0",
@@ -1254,17 +1258,15 @@ test:do_test(
 test:do_test(
     "func2-3.9.1",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', 2, -1)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "12")
+        return test:catchsql("SELECT SUBSTR(x'1234', 2, -2)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.9.2",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', 2, -2)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "12")
-
-
+        return test:catchsql("SELECT SUBSTR(x'1234', 2, -2)")
+    end,
+        {1, err})
 
 test:finish_test()
diff --git a/test/sql-tap/substr.test.lua b/test/sql-tap/substr.test.lua
index e7e6d7aca..45aae8506 100755
--- a/test/sql-tap/substr.test.lua
+++ b/test/sql-tap/substr.test.lua
@@ -1,6 +1,6 @@
 #!/usr/bin/env tarantool
 local test = require("sqltester")
-test:plan(93)
+test:plan(85)
 
 --!./tcltestrunner.lua
 -- 2007 May 14
@@ -74,17 +74,11 @@ substr_test("1.2", "abcdefg","2","1","b")
 substr_test("1.3", "abcdefg","1","2","ab")
 substr_test("1.4", "abcdefg","1","100","abcdefg")
 substr_test("1.5", "abcdefg","0","2","a")
-substr_test("1.6", "abcdefg","-1","1","g")
-substr_test("1.7", "abcdefg","-1","10","g")
-substr_test("1.8", "abcdefg","-5","3","cde")
-substr_test("1.9", "abcdefg","-7","3","abc")
-substr_test("1.10", "abcdefg","-100","98","abcde")
-substr_test("1.11", "abcdefg","5","-1","d")
-substr_test("1.12", "abcdefg","5","-4","abcd")
-substr_test("1.13", "abcdefg","5","-5","abcd")
-substr_test("1.14", "abcdefg","-5","-1","b")
-substr_test("1.15", "abcdefg","-5","-2","ab")
-substr_test("1.16", "abcdefg","-5","-3","ab")
+substr_test("1.6", "abcdefg","-1","1","")
+substr_test("1.7", "abcdefg","-1","10","abcdefg")
+substr_test("1.8", "abcdefg","-5","3","")
+substr_test("1.9", "abcdefg","-7","3","")
+substr_test("1.10", "abcdefg","-100","98","")
 substr_test("1.17", "abcdefg","100","200","")
 substr_test("1.18", "abcdefg","200","100","")
 -- Make sure NULL is returned if any parameter is NULL
@@ -144,21 +138,20 @@ test:do_test(
 substr_test("2.1", "ሴ⍅㑖","1","1","ሴ")
 substr_test("2.2", "ሴ⍅㑖","2","1","⍅")
 substr_test("2.3", "ሴ⍅㑖","1","2","ሴ⍅")
-substr_test("2.4", "ሴ⍅㑖","-1","1","㑖")
-substr_test("2.5", "aሴb⍅c㑖c","-5","3","b⍅c")
-substr_test("2.6", "aሴb⍅c㑖c","-2","-3","b⍅c")
+substr_test("2.4", "ሴ⍅㑖","-1","1","")
+substr_test("2.5", "aሴb⍅c㑖c","-5","3","")
 -- Basic functionality for BLOBs
 --
 subblob_test("3.1", "61626364656667","1","1","61")
 subblob_test("3.2", "61626364656667","2","1","62")
 subblob_test("3.3", "61626364656667","1","2","6162")
 subblob_test("3.4", "61626364656667","1","100","61626364656667")
-subblob_test("3.5", "61626364656667","0","2","61")
-subblob_test("3.6", "61626364656667","-1","1","67")
-subblob_test("3.7", "61626364656667","-1","10","67")
-subblob_test("3.8", "61626364656667","-5","3","636465")
-subblob_test("3.9", "61626364656667","-7","3","616263")
-subblob_test("3.10", "61626364656667","-100","98","6162636465")
+subblob_test("3.5", "61626364656667", "0", "2", "61")
+subblob_test("3.6", "61626364656667", "-1", "1", "")
+subblob_test("3.7", "61626364656667", "-1", "10", "61626364656667")
+subblob_test("3.8", "61626364656667", "-5", "3", "")
+subblob_test("3.9", "61626364656667","-7","3", "")
+subblob_test("3.10", "61626364656667", "-100", "98", "")
 subblob_test("3.11", "61626364656667","100","200","")
 subblob_test("3.12", "61626364656667","200","100","")
 -- If these blobs were strings, then they would contain multi-byte
@@ -168,9 +161,9 @@ subblob_test("3.12", "61626364656667","200","100","")
 subblob_test("4.1", "61E188B462E28D8563E3919663","1","1","61")
 subblob_test("4.2", "61E188B462E28D8563E3919663","2","1","E1")
 subblob_test("4.3", "61E188B462E28D8563E3919663","1","2","61E1")
-subblob_test("4.4", "61E188B462E28D8563E3919663","-2","1","96")
-subblob_test("4.5", "61E188B462E28D8563E3919663","-5","4","63E39196")
-subblob_test("4.6", "61E188B462E28D8563E3919663","-100","98","61E188B462E28D8563E391")
+subblob_test("4.4", "61E188B462E28D8563E3919663", "-2", "1", "")
+subblob_test("4.5", "61E188B462E28D8563E3919663", "-5", "4", "")
+subblob_test("4.6", "61E188B462E28D8563E3919663", "-100", "98", "")
 -- Two-argument SUBSTR
 --
 local function substr_2_test(id, string, idx, result)
@@ -193,7 +186,85 @@ local function substr_2_test(id, string, idx, result)
 end
 
 substr_2_test("5.1","abcdefghijklmnop","5","efghijklmnop")
-substr_2_test("5.2","abcdef","-5","bcdef")
+substr_2_test("5.2","abcdef","-5","abcdef")
 
+--
+-- gh-4145: Make sure SUBSTR() throws an error if the third argument is
+-- negative.
+--
+test:do_catchsql_test(
+    "substr-6.1",
+    [[
+        SELECT SUBSTR('12345', 1, -1);
+    ]],
+    {
+        1, [[Failed to execute SQL statement: ]]..
+           [[Length of the result cannot be less than 0]]
+    }
+)
+
+test:do_catchsql_test(
+    "substr-6.2",
+    [[
+        SELECT SUBSTR(x'3132333435', 1, -1);
+    ]],
+    {
+        1, [[Failed to execute SQL statement: ]]..
+           [[Length of the result cannot be less than 0]]
+    }
+)
+
+-- gh-4145: Make sure that SUBSTR() works according to ANSI.
+
+--
+-- Make sure SUBSTR() returns "" if the sum of the second and third arguments is
+-- 1 or less.
+--
+test:do_execsql_test(
+    "builtins-6.3",
+    [[
+        SELECT SUBSTR('asdfg', -10, 5), SUBSTR('asdfg', -4, 5);
+    ]],
+    {
+        '', ''
+    }
+)
+
+--
+-- Make sure that if the sum of the second and third arguments is more than 1
+-- and the second argument is negative, the result starts from the start of the
+-- string and length of the result will be one less than sum of the  second and
+-- third arguments.
+--
+test:do_execsql_test(
+    "builtins-6.4",
+    [[
+        SELECT SUBSTR('123456789', -5, 10);
+    ]],
+    {
+        '1234'
+    }
+)
+
+-- Make sure SUBSTR() can work with big INTEGERs.
+test:do_execsql_test(
+    "builtins-6.5",
+    [[
+        SELECT SUBSTR('123456789', -9223372036854775808, 9223372036854775812);
+    ]],
+    {
+        '123'
+    }
+)
+
+test:do_execsql_test(
+    "builtins-6.6",
+    [[
+        SELECT SUBSTR('123456789', 0, 18000000000000000000);
+    ]],
+    {
+        '123456789'
+    }
+)
 
 test:finish_test()

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [Tarantool-patches] [PATCH v1 7/8] sql: rework SUBSTR() function
  2021-10-01 16:29 ` [Tarantool-patches] [PATCH v1 7/8] sql: rework SUBSTR() function Mergen Imeev via Tarantool-patches
@ 2021-10-08 22:02   ` Vladislav Shpilevoy via Tarantool-patches
  2021-10-20 17:15     ` Mergen Imeev via Tarantool-patches
  0 siblings, 1 reply; 15+ messages in thread
From: Vladislav Shpilevoy via Tarantool-patches @ 2021-10-08 22:02 UTC (permalink / raw)
  To: imeevma; +Cc: tarantool-patches

Thanks for the patch!

On 01.10.2021 18:29, Mergen Imeev via Tarantool-patches wrote:
> This patch makes SUBSTR() work according to ANSI rules for SUBSTRING()
> function. Also, SUBSTR() can now work correctly with large INTEGER
> values. The SUBSTR() syntax has not changed.

Does not make much sense given that Mem.n is just int. You can't
have strings or blobs larger than that.

> Part of #4145
> 
> @TarantoolBot document
> Title: SUBSTR() function
> 
> SUBSTR() now works according to the ANSI rules for SUBSTRING(), but with
> no syntax changes. What changed:
> 1) if the third argument is specified and it is less than 0, an error is
> thrown;
> 2) if the sum of the second and third arguments is less than 1, an empty
> string is returned;
> 3) if the second argument is less than 0, and the sum of the second and
> third arguments is greater than 1, then the result is equal to the
> result of SUBSTR() with the second argument equal to 1 and the third
> argument equal to the sum of the original second and third arguments
> minus 1.

I don't understand how it works now. What are the arguments? What
do they do? Can you explain fully? I see that a lot of tests now has
turned into errors and I don't understand why did they stop working.

In the code I couldn't find any comments.

^ permalink raw reply	[flat|nested] 15+ messages in thread

* [Tarantool-patches] [PATCH v1 7/8] sql: rework SUBSTR() function
  2021-10-01 16:29 Mergen Imeev via Tarantool-patches
@ 2021-10-01 16:29 ` Mergen Imeev via Tarantool-patches
  2021-10-08 22:02   ` Vladislav Shpilevoy via Tarantool-patches
  0 siblings, 1 reply; 15+ messages in thread
From: Mergen Imeev via Tarantool-patches @ 2021-10-01 16:29 UTC (permalink / raw)
  To: v.shpilevoy; +Cc: tarantool-patches

This patch makes SUBSTR() work according to ANSI rules for SUBSTRING()
function. Also, SUBSTR() can now work correctly with large INTEGER
values. The SUBSTR() syntax has not changed.

Part of #4145

@TarantoolBot document
Title: SUBSTR() function

SUBSTR() now works according to the ANSI rules for SUBSTRING(), but with
no syntax changes. What changed:
1) if the third argument is specified and it is less than 0, an error is
thrown;
2) if the sum of the second and third arguments is less than 1, an empty
string is returned;
3) if the second argument is less than 0, and the sum of the second and
third arguments is greater than 1, then the result is equal to the
result of SUBSTR() with the second argument equal to 1 and the third
argument equal to the sum of the original second and third arguments
minus 1.
---
 src/box/sql/func.c           | 264 ++++++++++++++++++++---------------
 test/sql-tap/func.test.lua   |  16 +--
 test/sql-tap/func2.test.lua  | 150 ++++++++++----------
 test/sql-tap/substr.test.lua | 121 ++++++++++++----
 4 files changed, 330 insertions(+), 221 deletions(-)

diff --git a/src/box/sql/func.c b/src/box/sql/func.c
index 415a92738..1b4d52225 100644
--- a/src/box/sql/func.c
+++ b/src/box/sql/func.c
@@ -592,6 +592,152 @@ func_position_characters(struct sql_context *ctx, int argc, struct Mem *argv)
 	return mem_set_uint(ctx->pOut, 0);
 }
 
+/** Implementation of the SUBSTR() function. */
+int
+substr_normalize(int64_t base_start, bool is_start_neg, uint64_t base_length,
+		 uint64_t *start, uint64_t *length)
+{
+	if (!is_start_neg && base_start > 0) {
+		*start = (uint64_t)base_start - 1;
+		*length = base_length;
+		return 0;
+	}
+	*start = 0;
+	if (base_length == 0) {
+		*length = 0;
+		return 0;
+	}
+	/*
+	 * We are subtracting 1 from base_length instead of subtracting from
+	 * base_start, since base_start can be INT64_MIN. At the same time,
+	 * base_length is not less than 1.
+	 */
+	int64_t a = base_start;
+	int64_t b = (int64_t)(base_length - 1);
+	int64_t res;
+	bool is_neg;
+	/*
+	 * Integer cannot overflow since non-positive value is added to positive
+	 * value.
+	 */
+	if (sql_add_int(a, a != 0, b, false, &res, &is_neg) != 0) {
+		diag_set(ClientError, ER_SQL_EXECUTE, "integer is overflowed");
+		return -1;
+	}
+	*length = is_neg ? 0 : (uint64_t)res;
+	return 0;
+}
+
+static void
+func_substr_octets(struct sql_context *ctx, int argc, struct Mem *argv)
+{
+	assert(argc == 2 || argc == 3);
+	if (mem_is_any_null(&argv[0], &argv[1]))
+		return;
+	assert(mem_is_bytes(&argv[0]) && mem_is_int(&argv[1]));
+
+	bool is_str = mem_is_str(&argv[0]);
+	uint64_t size = argv[0].n;
+
+	if (argc == 2) {
+		uint64_t start = mem_is_uint(&argv[1]) && argv[1].u.u > 1 ?
+				 argv[1].u.u - 1 : 0;
+		if (start >= size)
+			return return_empty_str(ctx, is_str);
+		char *s = &argv[0].z[start];
+		uint64_t n = size - start;
+		ctx->is_aborted = is_str ? mem_copy_str(ctx->pOut, s, n) != 0 :
+				  mem_copy_bin(ctx->pOut, s, n) != 0;
+		return;
+	}
+
+	assert(argc == 3);
+	if (mem_is_null(&argv[2]))
+		return;
+	assert(mem_is_int(&argv[2]));
+	if (!mem_is_uint(&argv[2])) {
+		diag_set(ClientError, ER_SQL_EXECUTE, "Length of the result "
+			 "cannot be less than 0");
+		ctx->is_aborted = true;
+		return;
+	}
+	uint64_t start;
+	uint64_t length;
+	if (substr_normalize(argv[1].u.i, !mem_is_uint(&argv[1]), argv[2].u.u,
+	    &start, &length) != 0) {
+		ctx->is_aborted = true;
+		return;
+	}
+	if (start >= size || length == 0)
+		return return_empty_str(ctx, is_str);
+	char *str = &argv[0].z[start];
+	uint64_t len = MIN(size - start, length);
+	ctx->is_aborted = is_str ? mem_copy_str(ctx->pOut, str, len) != 0 :
+			  mem_copy_bin(ctx->pOut, str, len) != 0;
+}
+
+static void
+func_substr_characters(struct sql_context *ctx, int argc, struct Mem *argv)
+{
+	assert(argc == 2 || argc == 3);
+	(void)argc;
+	if (mem_is_any_null(&argv[0], &argv[1]))
+		return;
+	assert(mem_is_str(&argv[0]) && mem_is_int(&argv[1]));
+
+	uint64_t size = argv[0].n;
+
+	if (argc == 2) {
+		uint64_t start = mem_is_uint(&argv[1]) && argv[1].u.u > 1 ?
+				 argv[1].u.u - 1 : 0;
+		char *str = argv[0].z;
+		uint64_t s = 0;
+		for (uint64_t i = 0; i < start && s < size; ++i)
+			s += utf8_len_char(str[s]);
+
+		if (s >= size)
+			return mem_set_str_static(ctx->pOut, "", 0);
+		uint64_t len = size - s;
+		if (mem_copy_str(ctx->pOut, &str[s], len) != 0)
+			ctx->is_aborted = true;
+		return;
+	}
+
+	assert(argc == 3);
+	if (mem_is_null(&argv[2]))
+		return;
+	assert(mem_is_int(&argv[2]));
+	if (!mem_is_uint(&argv[2])) {
+		diag_set(ClientError, ER_SQL_EXECUTE, "Length of the result "
+			 "cannot be less than 0");
+		ctx->is_aborted = true;
+		return;
+	}
+	uint64_t start;
+	uint64_t length;
+	if (substr_normalize(argv[1].u.i, !mem_is_uint(&argv[1]), argv[2].u.u,
+	    &start, &length) != 0) {
+		ctx->is_aborted = true;
+		return;
+	}
+	if (length == 0)
+		return mem_set_str_static(ctx->pOut, "", 0);
+
+	char *str = argv[0].z;
+	uint64_t s = 0;
+	for (uint64_t i = 0; i < start && s < size; ++i)
+		s += utf8_len_char(str[s]);
+	uint64_t e = s;
+	for (uint64_t i = 0; i < length && e < size; ++i)
+		e += utf8_len_char(str[e]);
+	if (s >= size)
+		return mem_set_str_static(ctx->pOut, "", 0);
+
+	uint64_t len = MIN(e, size) - s;
+	if (mem_copy_str(ctx->pOut, &str[s], len) != 0)
+		ctx->is_aborted = true;
+}
+
 static const unsigned char *
 mem_as_ustr(struct Mem *mem)
 {
@@ -789,116 +935,6 @@ printfFunc(struct sql_context *context, int argc, struct Mem *argv)
 	}
 }
 
-/*
- * Implementation of the substr() function.
- *
- * substr(x,p1,p2)  returns p2 characters of x[] beginning with p1.
- * p1 is 1-indexed.  So substr(x,1,1) returns the first character
- * of x.  If x is text, then we actually count UTF-8 characters.
- * If x is a blob, then we count bytes.
- *
- * If p1 is negative, then we begin abs(p1) from the end of x[].
- *
- * If p2 is negative, return the p2 characters preceding p1.
- */
-static void
-substrFunc(struct sql_context *context, int argc, struct Mem *argv)
-{
-	const unsigned char *z;
-	const unsigned char *z2;
-	int len;
-	int p0type;
-	int64_t p1, p2;
-	int negP2 = 0;
-
-	if (argc != 2 && argc != 3) {
-		diag_set(ClientError, ER_FUNC_WRONG_ARG_COUNT, "SUBSTR",
-			 "1 or 2", argc);
-		context->is_aborted = true;
-		return;
-	}
-	if (mem_is_null(&argv[1]) || (argc == 3 && mem_is_null(&argv[2])))
-		return;
-	p0type = sql_value_type(&argv[0]);
-	p1 = mem_get_int_unsafe(&argv[1]);
-	if (p0type == MP_BIN) {
-		z = mem_as_bin(&argv[0]);
-		len = mem_len_unsafe(&argv[0]);
-		if (z == 0)
-			return;
-		assert(len == mem_len_unsafe(&argv[0]));
-	} else {
-		z = mem_as_ustr(&argv[0]);
-		if (z == 0)
-			return;
-		len = 0;
-		if (p1 < 0)
-			len = sql_utf8_char_count(z, mem_len_unsafe(&argv[0]));
-	}
-	if (argc == 3) {
-		p2 = mem_get_int_unsafe(&argv[2]);
-		if (p2 < 0) {
-			p2 = -p2;
-			negP2 = 1;
-		}
-	} else {
-		p2 = sql_context_db_handle(context)->
-		    aLimit[SQL_LIMIT_LENGTH];
-	}
-	if (p1 < 0) {
-		p1 += len;
-		if (p1 < 0) {
-			p2 += p1;
-			if (p2 < 0)
-				p2 = 0;
-			p1 = 0;
-		}
-	} else if (p1 > 0) {
-		p1--;
-	} else if (p2 > 0) {
-		p2--;
-	}
-	if (negP2) {
-		p1 -= p2;
-		if (p1 < 0) {
-			p2 += p1;
-			p1 = 0;
-		}
-	}
-	assert(p1 >= 0 && p2 >= 0);
-	if (p0type != MP_BIN) {
-		/*
-		 * In the code below 'cnt' and 'n_chars' is
-		 * used because '\0' is not supposed to be
-		 * end-of-string symbol.
-		 */
-		int byte_size = mem_len_unsafe(&argv[0]);
-		int n_chars = sql_utf8_char_count(z, byte_size);
-		int cnt = 0;
-		int i = 0;
-		while (cnt < n_chars && p1) {
-			SQL_UTF8_FWD_1(z, i, byte_size);
-			cnt++;
-			p1--;
-		}
-		z += i;
-		i = 0;
-		for (z2 = z; cnt < n_chars && p2; p2--) {
-			SQL_UTF8_FWD_1(z2, i, byte_size);
-			cnt++;
-		}
-		z2 += i;
-		mem_copy_str(context->pOut, (char *)z, z2 - z);
-	} else {
-		if (p1 + p2 > len) {
-			p2 = len - p1;
-			if (p2 < 0)
-				p2 = 0;
-		}
-		mem_copy_bin(context->pOut, (char *)&z[p1], p2);
-	}
-}
-
 /*
  * Implementation of the round() function
  */
@@ -1953,15 +1989,15 @@ static struct sql_func_definition definitions[] = {
 	{"SOUNDEX", 1, {FIELD_TYPE_STRING}, FIELD_TYPE_STRING, soundexFunc,
 	 NULL},
 	{"SUBSTR", 2, {FIELD_TYPE_STRING, FIELD_TYPE_INTEGER},
-	 FIELD_TYPE_STRING, substrFunc, NULL},
+	 FIELD_TYPE_STRING, func_substr_characters, NULL},
 	{"SUBSTR", 3,
 	 {FIELD_TYPE_STRING, FIELD_TYPE_INTEGER, FIELD_TYPE_INTEGER},
-	 FIELD_TYPE_STRING, substrFunc, NULL},
+	 FIELD_TYPE_STRING, func_substr_characters, NULL},
 	{"SUBSTR", 2, {FIELD_TYPE_VARBINARY, FIELD_TYPE_INTEGER},
-	 FIELD_TYPE_VARBINARY, substrFunc, NULL},
+	 FIELD_TYPE_VARBINARY, func_substr_octets, NULL},
 	{"SUBSTR", 3,
 	 {FIELD_TYPE_VARBINARY, FIELD_TYPE_INTEGER, FIELD_TYPE_INTEGER},
-	 FIELD_TYPE_VARBINARY, substrFunc, NULL},
+	 FIELD_TYPE_VARBINARY, func_substr_octets, NULL},
 	{"SUM", 1, {FIELD_TYPE_INTEGER}, FIELD_TYPE_INTEGER, step_sum, NULL},
 	{"SUM", 1, {FIELD_TYPE_DOUBLE}, FIELD_TYPE_DOUBLE, step_sum, NULL},
 	{"TOTAL", 1, {FIELD_TYPE_INTEGER}, FIELD_TYPE_DOUBLE, step_total,
diff --git a/test/sql-tap/func.test.lua b/test/sql-tap/func.test.lua
index 416f27d69..dc4dfdc0e 100755
--- a/test/sql-tap/func.test.lua
+++ b/test/sql-tap/func.test.lua
@@ -139,7 +139,7 @@ test:do_execsql_test(
         SELECT substr(t1,-1,1) FROM tbl1 ORDER BY t1
     ]], {
         -- <func-2.3>
-        "e", "s", "m", "e", "s"
+        "", "", "", "", ""
         -- </func-2.3>
     })
 
@@ -149,7 +149,7 @@ test:do_execsql_test(
         SELECT substr(t1,-1,2) FROM tbl1 ORDER BY t1
     ]], {
         -- <func-2.4>
-        "e", "s", "m", "e", "s"
+        "", "", "", "", ""
         -- </func-2.4>
     })
 
@@ -159,7 +159,7 @@ test:do_execsql_test(
         SELECT substr(t1,-2,1) FROM tbl1 ORDER BY t1
     ]], {
         -- <func-2.5>
-        "e", "i", "a", "r", "i"
+        "", "", "", "", ""
         -- </func-2.5>
     })
 
@@ -169,7 +169,7 @@ test:do_execsql_test(
         SELECT substr(t1,-2,2) FROM tbl1 ORDER BY t1
     ]], {
         -- <func-2.6>
-        "ee", "is", "am", "re", "is"
+        "", "", "", "", ""
         -- </func-2.6>
     })
 
@@ -179,7 +179,7 @@ test:do_execsql_test(
         SELECT substr(t1,-4,2) FROM tbl1 ORDER BY t1
     ]], {
         -- <func-2.7>
-        "fr", "", "gr", "wa", "th"
+        "", "", "", "", ""
         -- </func-2.7>
     })
 
@@ -288,7 +288,7 @@ if ("ሴ" ~= "u1234") then
             SELECT substr(t1,-1,1) FROM tbl1 ORDER BY t1
         ]], {
             -- <func-3.8>
-            "8", "s", "s", "o"
+            "", "", "", ""
             -- </func-3.8>
         })
 
@@ -298,7 +298,7 @@ if ("ሴ" ~= "u1234") then
             SELECT substr(t1,-3,2) FROM tbl1 ORDER BY t1
         ]], {
             -- <func-3.9>
-            "F-", "er", "in", "ሴh"
+            "", "", "", ""
             -- </func-3.9>
         })
 
@@ -308,7 +308,7 @@ if ("ሴ" ~= "u1234") then
             SELECT substr(t1,-4,3) FROM tbl1 ORDER BY t1
         ]], {
             -- <func-3.10>
-            "TF-", "ter", "ain", "iሴh"
+            "", "", "", ""
             -- </func-3.10>
         })
 
diff --git a/test/sql-tap/func2.test.lua b/test/sql-tap/func2.test.lua
index 792f020f1..b786b4d96 100755
--- a/test/sql-tap/func2.test.lua
+++ b/test/sql-tap/func2.test.lua
@@ -162,7 +162,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -1)
     ]], {
         -- <func2-1.11>
-        "s"
+        "Supercalifragilisticexpialidocious"
         -- </func2-1.11>
     })
 
@@ -172,7 +172,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -2)
     ]], {
         -- <func2-1.12>
-        "us"
+        "Supercalifragilisticexpialidocious"
         -- </func2-1.12>
     })
 
@@ -182,7 +182,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -30)
     ]], {
         -- <func2-1.13>
-        "rcalifragilisticexpialidocious"
+        "Supercalifragilisticexpialidocious"
         -- </func2-1.13>
     })
 
@@ -344,7 +344,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -1, 1)
     ]], {
         -- <func2-1.25.1>
-        "s"
+        ""
         -- </func2-1.25.1>
     })
 
@@ -354,7 +354,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -1, 2)
     ]], {
         -- <func2-1.25.2>
-        "s"
+        ""
         -- </func2-1.25.2>
     })
 
@@ -364,7 +364,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -2, 1)
     ]], {
         -- <func2-1.26>
-        "u"
+        ""
         -- </func2-1.26>
     })
 
@@ -374,7 +374,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -30, 1)
     ]], {
         -- <func2-1.27>
-        "r"
+        ""
         -- </func2-1.27>
     })
 
@@ -394,7 +394,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -34, 1)
     ]], {
         -- <func2-1.28.1>
-        "S"
+        ""
         -- </func2-1.28.1>
     })
 
@@ -404,7 +404,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -34, 2)
     ]], {
         -- <func2-1.28.2>
-        "Su"
+        ""
         -- </func2-1.28.2>
     })
 
@@ -424,7 +424,7 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -35, 2)
     ]], {
         -- <func2-1.29.2>
-        "S"
+        ""
         -- </func2-1.29.2>
     })
 
@@ -464,11 +464,13 @@ test:do_execsql_test(
         SELECT SUBSTR('Supercalifragilisticexpialidocious', -36, 3)
     ]], {
         -- <func2-1.30.3>
-        "S"
+        ""
         -- </func2-1.30.3>
     })
 
 -- p1 is 1-indexed, p2 length to return, p2<0 return p2 chars before p1
+local err = [[Failed to execute SQL statement: Length of the result cannot ]]..
+            [[be less than 0]]
 test:do_execsql_test(
     "func2-1.31.0",
     [[
@@ -479,23 +481,23 @@ test:do_execsql_test(
         -- </func2-1.31.0>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.31.1",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 0, -1)
     ]], {
         -- <func2-1.31.1>
-        ""
+        1, err
         -- </func2-1.31.1>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.31.2",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 0, -2)
     ]], {
         -- <func2-1.31.2>
-        ""
+        1, err
         -- </func2-1.31.2>
     })
 
@@ -509,13 +511,13 @@ test:do_execsql_test(
         -- </func2-1.32.0>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.32.1",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 1, -1)
     ]], {
         -- <func2-1.32.1>
-        ""
+        1, err
         -- </func2-1.32.1>
     })
 
@@ -529,23 +531,23 @@ test:do_execsql_test(
         -- </func2-1.33.0>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.33.1",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 2, -1)
     ]], {
         -- <func2-1.33.1>
-        "S"
+        1, err
         -- </func2-1.33.1>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.33.2",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 2, -2)
     ]], {
         -- <func2-1.33.2>
-        "S"
+        1, err
         -- </func2-1.33.2>
     })
 
@@ -559,63 +561,63 @@ test:do_execsql_test(
         -- </func2-1.34.0>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.34.1",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 3, -1)
     ]], {
         -- <func2-1.34.1>
-        "u"
+        1, err
         -- </func2-1.34.1>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.34.2",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 3, -2)
     ]], {
         -- <func2-1.34.2>
-        "Su"
+        1, err
         -- </func2-1.34.2>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.35.1",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 30, -1)
     ]], {
         -- <func2-1.35.1>
-        "o"
+        1, err
         -- </func2-1.35.1>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.35.2",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 30, -2)
     ]], {
         -- <func2-1.35.2>
-        "do"
+        1, err
         -- </func2-1.35.2>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.36",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 34, -1)
     ]], {
         -- <func2-1.36>
-        "u"
+        1, err
         -- </func2-1.36>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.37",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 35, -1)
     ]], {
         -- <func2-1.37>
-        "s"
+        1, err
         -- </func2-1.37>
     })
 
@@ -629,23 +631,23 @@ test:do_execsql_test(
         -- </func2-1.38.0>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.38.1",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 36, -1)
     ]], {
         -- <func2-1.38.1>
-        ""
+        1, err
         -- </func2-1.38.1>
     })
 
-test:do_execsql_test(
+test:do_catchsql_test(
     "func2-1.38.2",
     [[
         SELECT SUBSTR('Supercalifragilisticexpialidocious', 36, -2)
     ]], {
         -- <func2-1.38.2>
-        "s"
+        1, err
         -- </func2-1.38.2>
     })
 
@@ -993,7 +995,7 @@ if ("ሴ" ~= "u1234")
             SELECT SUBSTR('ሴ', -1, 1)
         ]], {
             -- <func2-2.8.1>
-            "ሴ"
+            ""
             -- </func2-2.8.1>
         })
 
@@ -1003,7 +1005,7 @@ if ("ሴ" ~= "u1234")
             SELECT SUBSTR('ሴ', -1, 2)
         ]], {
             -- <func2-2.8.2>
-            "ሴ"
+            ""
             -- </func2-2.8.2>
         })
 
@@ -1130,21 +1132,21 @@ test:do_test(
     function()
         local blob = test:execsql "SELECT SUBSTR(x'1234', -1, 1)"
         return bin_to_hex(test.lindex(blob, 0))
-    end, "34")
+    end, "")
 
 test:do_test(
     "func2-3.4.2",
     function()
         local blob = test:execsql "SELECT SUBSTR(x'1234', -1, 2)"
         return bin_to_hex(test.lindex(blob, 0))
-    end, "34")
+    end, "")
 
 test:do_test(
     "func2-3.4.3",
     function()
         local blob = test:execsql "SELECT SUBSTR(x'1234', -1, 3)"
         return bin_to_hex(test.lindex(blob, 0))
-    end, "34")
+    end, "12")
 
 test:do_test(
     "func2-3.5.0",
@@ -1158,21 +1160,21 @@ test:do_test(
     function()
         local blob = test:execsql "SELECT SUBSTR(x'1234', -2, 1)"
         return bin_to_hex(test.lindex(blob, 0))
-    end, "12")
+    end, "")
 
 test:do_test(
     "func2-3.5.2",
     function()
         local blob = test:execsql "SELECT SUBSTR(x'1234', -2, 2)"
         return bin_to_hex(test.lindex(blob, 0))
-    end, "1234")
+    end, "")
 
 test:do_test(
     "func2-3.5.3",
     function()
         local blob = test:execsql "SELECT SUBSTR(x'1234', -2, 3)"
         return bin_to_hex(test.lindex(blob, 0))
-    end, "1234")
+    end, "")
 
 test:do_test(
     "func2-3.6.0",
@@ -1181,26 +1183,28 @@ test:do_test(
         return bin_to_hex(test.lindex(blob, 0))
     end, "")
 
+local err = [[Failed to execute SQL statement: Length of the result cannot ]]..
+            [[be less than 0]]
 test:do_test(
     "func2-3.6.1",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', -1, -1)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "12")
+        return test:catchsql("SELECT SUBSTR(x'1234', -1, -1)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.6.2",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', -1, -2)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "12")
+        return test:catchsql("SELECT SUBSTR(x'1234', -1, -2)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.6.3",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', -1, -3)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "12")
+        return test:catchsql("SELECT SUBSTR(x'1234', -1, -3)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.7.0",
@@ -1212,16 +1216,16 @@ test:do_test(
 test:do_test(
     "func2-3.7.1",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', -2, -1)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "")
+        return test:catchsql("SELECT SUBSTR(x'1234', -2, -1)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.7.2",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', -2, -2)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "")
+        return test:catchsql("SELECT SUBSTR(x'1234', -2, -2)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.8.0",
@@ -1233,16 +1237,16 @@ test:do_test(
 test:do_test(
     "func2-3.8.1",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', 1, -1)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "")
+        return test:catchsql("SELECT SUBSTR(x'1234', 1, -1)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.8.2",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', 1, -2)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "")
+        return test:catchsql("SELECT SUBSTR(x'1234', 1, -2)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.9.0",
@@ -1254,17 +1258,15 @@ test:do_test(
 test:do_test(
     "func2-3.9.1",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', 2, -1)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "12")
+        return test:catchsql("SELECT SUBSTR(x'1234', 2, -2)")
+    end,
+        {1, err})
 
 test:do_test(
     "func2-3.9.2",
     function()
-        local blob = test:execsql "SELECT SUBSTR(x'1234', 2, -2)"
-        return bin_to_hex(test.lindex(blob, 0))
-    end, "12")
-
-
+        return test:catchsql("SELECT SUBSTR(x'1234', 2, -2)")
+    end,
+        {1, err})
 
 test:finish_test()
diff --git a/test/sql-tap/substr.test.lua b/test/sql-tap/substr.test.lua
index e7e6d7aca..45aae8506 100755
--- a/test/sql-tap/substr.test.lua
+++ b/test/sql-tap/substr.test.lua
@@ -1,6 +1,6 @@
 #!/usr/bin/env tarantool
 local test = require("sqltester")
-test:plan(93)
+test:plan(85)
 
 --!./tcltestrunner.lua
 -- 2007 May 14
@@ -74,17 +74,11 @@ substr_test("1.2", "abcdefg","2","1","b")
 substr_test("1.3", "abcdefg","1","2","ab")
 substr_test("1.4", "abcdefg","1","100","abcdefg")
 substr_test("1.5", "abcdefg","0","2","a")
-substr_test("1.6", "abcdefg","-1","1","g")
-substr_test("1.7", "abcdefg","-1","10","g")
-substr_test("1.8", "abcdefg","-5","3","cde")
-substr_test("1.9", "abcdefg","-7","3","abc")
-substr_test("1.10", "abcdefg","-100","98","abcde")
-substr_test("1.11", "abcdefg","5","-1","d")
-substr_test("1.12", "abcdefg","5","-4","abcd")
-substr_test("1.13", "abcdefg","5","-5","abcd")
-substr_test("1.14", "abcdefg","-5","-1","b")
-substr_test("1.15", "abcdefg","-5","-2","ab")
-substr_test("1.16", "abcdefg","-5","-3","ab")
+substr_test("1.6", "abcdefg","-1","1","")
+substr_test("1.7", "abcdefg","-1","10","abcdefg")
+substr_test("1.8", "abcdefg","-5","3","")
+substr_test("1.9", "abcdefg","-7","3","")
+substr_test("1.10", "abcdefg","-100","98","")
 substr_test("1.17", "abcdefg","100","200","")
 substr_test("1.18", "abcdefg","200","100","")
 -- Make sure NULL is returned if any parameter is NULL
@@ -144,21 +138,20 @@ test:do_test(
 substr_test("2.1", "ሴ⍅㑖","1","1","ሴ")
 substr_test("2.2", "ሴ⍅㑖","2","1","⍅")
 substr_test("2.3", "ሴ⍅㑖","1","2","ሴ⍅")
-substr_test("2.4", "ሴ⍅㑖","-1","1","㑖")
-substr_test("2.5", "aሴb⍅c㑖c","-5","3","b⍅c")
-substr_test("2.6", "aሴb⍅c㑖c","-2","-3","b⍅c")
+substr_test("2.4", "ሴ⍅㑖","-1","1","")
+substr_test("2.5", "aሴb⍅c㑖c","-5","3","")
 -- Basic functionality for BLOBs
 --
 subblob_test("3.1", "61626364656667","1","1","61")
 subblob_test("3.2", "61626364656667","2","1","62")
 subblob_test("3.3", "61626364656667","1","2","6162")
 subblob_test("3.4", "61626364656667","1","100","61626364656667")
-subblob_test("3.5", "61626364656667","0","2","61")
-subblob_test("3.6", "61626364656667","-1","1","67")
-subblob_test("3.7", "61626364656667","-1","10","67")
-subblob_test("3.8", "61626364656667","-5","3","636465")
-subblob_test("3.9", "61626364656667","-7","3","616263")
-subblob_test("3.10", "61626364656667","-100","98","6162636465")
+subblob_test("3.5", "61626364656667", "0", "2", "61")
+subblob_test("3.6", "61626364656667", "-1", "1", "")
+subblob_test("3.7", "61626364656667", "-1", "10", "61626364656667")
+subblob_test("3.8", "61626364656667", "-5", "3", "")
+subblob_test("3.9", "61626364656667","-7","3", "")
+subblob_test("3.10", "61626364656667", "-100", "98", "")
 subblob_test("3.11", "61626364656667","100","200","")
 subblob_test("3.12", "61626364656667","200","100","")
 -- If these blobs were strings, then they would contain multi-byte
@@ -168,9 +161,9 @@ subblob_test("3.12", "61626364656667","200","100","")
 subblob_test("4.1", "61E188B462E28D8563E3919663","1","1","61")
 subblob_test("4.2", "61E188B462E28D8563E3919663","2","1","E1")
 subblob_test("4.3", "61E188B462E28D8563E3919663","1","2","61E1")
-subblob_test("4.4", "61E188B462E28D8563E3919663","-2","1","96")
-subblob_test("4.5", "61E188B462E28D8563E3919663","-5","4","63E39196")
-subblob_test("4.6", "61E188B462E28D8563E3919663","-100","98","61E188B462E28D8563E391")
+subblob_test("4.4", "61E188B462E28D8563E3919663", "-2", "1", "")
+subblob_test("4.5", "61E188B462E28D8563E3919663", "-5", "4", "")
+subblob_test("4.6", "61E188B462E28D8563E3919663", "-100", "98", "")
 -- Two-argument SUBSTR
 --
 local function substr_2_test(id, string, idx, result)
@@ -193,7 +186,85 @@ local function substr_2_test(id, string, idx, result)
 end
 
 substr_2_test("5.1","abcdefghijklmnop","5","efghijklmnop")
-substr_2_test("5.2","abcdef","-5","bcdef")
+substr_2_test("5.2","abcdef","-5","abcdef")
 
+--
+-- gh-4145: Make sure SUBSTR() throws an error if the third argument is
+-- negative.
+--
+test:do_catchsql_test(
+    "substr-6.1",
+    [[
+        SELECT SUBSTR('12345', 1, -1);
+    ]],
+    {
+        1, [[Failed to execute SQL statement: ]]..
+           [[Length of the result cannot be less than 0]]
+    }
+)
+
+test:do_catchsql_test(
+    "substr-6.2",
+    [[
+        SELECT SUBSTR(x'3132333435', 1, -1);
+    ]],
+    {
+        1, [[Failed to execute SQL statement: ]]..
+           [[Length of the result cannot be less than 0]]
+    }
+)
+
+-- gh-4145: Make sure that SUBSTR() works according to ANSI.
+
+--
+-- Make sure SUBSTR() returns "" if the sum of the second and third arguments is
+-- 1 or less.
+--
+test:do_execsql_test(
+    "builtins-6.3",
+    [[
+        SELECT SUBSTR('asdfg', -10, 5), SUBSTR('asdfg', -4, 5);
+    ]],
+    {
+        '', ''
+    }
+)
+
+--
+-- Make sure that if the sum of the second and third arguments is more than 1
+-- and the second argument is negative, the result starts from the start of the
+-- string and length of the result will be one less than sum of the  second and
+-- third arguments.
+--
+test:do_execsql_test(
+    "builtins-6.4",
+    [[
+        SELECT SUBSTR('123456789', -5, 10);
+    ]],
+    {
+        '1234'
+    }
+)
+
+-- Make sure SUBSTR() can work with big INTEGERs.
+test:do_execsql_test(
+    "builtins-6.5",
+    [[
+        SELECT SUBSTR('123456789', -9223372036854775808, 9223372036854775812);
+    ]],
+    {
+        '123'
+    }
+)
+
+test:do_execsql_test(
+    "builtins-6.6",
+    [[
+        SELECT SUBSTR('123456789', 0, 18000000000000000000);
+    ]],
+    {
+        '123456789'
+    }
+)
 
 test:finish_test()
-- 
2.25.1


^ permalink raw reply	[flat|nested] 15+ messages in thread

end of thread, other threads:[~2021-11-11 11:03 UTC | newest]

Thread overview: 15+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-11-11 10:45 [Tarantool-patches] [PATCH v1 0/8] Rework standard function Mergen Imeev via Tarantool-patches
2021-11-11 10:45 ` [Tarantool-patches] [PATCH v1 1/8] sql: refactor ABS() funcion Mergen Imeev via Tarantool-patches
2021-11-11 10:45 ` [Tarantool-patches] [PATCH v1 2/8] sql: rework CHAR_LENGTH() function Mergen Imeev via Tarantool-patches
2021-11-11 10:45 ` [Tarantool-patches] [PATCH v1 3/8] sql: refactor UPPER() and LOWER() functions Mergen Imeev via Tarantool-patches
2021-11-11 10:45 ` [Tarantool-patches] [PATCH v1 4/8] sql: refactor NULLIF() function Mergen Imeev via Tarantool-patches
2021-11-11 10:45 ` [Tarantool-patches] [PATCH v1 5/8] sql: rework TRIM() function Mergen Imeev via Tarantool-patches
2021-11-11 10:45 ` [Tarantool-patches] [PATCH v1 6/8] sql: rework POSITION() function Mergen Imeev via Tarantool-patches
2021-11-11 10:45 ` [Tarantool-patches] [PATCH v1 7/8] sql: rework SUBSTR() function Mergen Imeev via Tarantool-patches
2021-11-11 10:45 ` [Tarantool-patches] [PATCH v1 8/8] sql: refactor LIKE() function Mergen Imeev via Tarantool-patches
2021-11-11 10:59 ` [Tarantool-patches] [PATCH v1 0/8] Rework standard function Kirill Yukhin via Tarantool-patches
  -- strict thread matches above, loose matches on Subject: below --
2021-10-01 16:29 Mergen Imeev via Tarantool-patches
2021-10-01 16:29 ` [Tarantool-patches] [PATCH v1 7/8] sql: rework SUBSTR() function Mergen Imeev via Tarantool-patches
2021-10-08 22:02   ` Vladislav Shpilevoy via Tarantool-patches
2021-10-20 17:15     ` Mergen Imeev via Tarantool-patches
2021-10-28 22:13       ` Vladislav Shpilevoy via Tarantool-patches
2021-11-01 10:45         ` Mergen Imeev via Tarantool-patches

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