[Tarantool-patches] [PATCH v1 7/8] sql: rework SUBSTR() function

imeevma at tarantool.org imeevma at tarantool.org
Fri Oct 1 19:29:40 MSK 2021


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



More information about the Tarantool-patches mailing list