[Tarantool-patches] [PATCH v1 3/5] sql: create SET command

[imeevma@tarantool.org]

This patch creates the SET command for SQL, which will be used
instead of pragmas that modify SQL settings.

Part of #4511

@TarantoolBot document
Title: SET SQL command
The SET SQL command is used to change SQL settings.

Currently available SQL settings:
'defer_foreign_keys'
'full_column_names'
'recursive_triggers'
'reverse_unordered_selects'
'sql_compound_select_limit'
'sql_default_engine'

In addition, SQL debugging settings can also be changed using this
command in the debug build:
'parser_trace'
'select_trace'
'sql_trace'
'vdbe_addoptrace'
'vdbe_debug'
'vdbe_eqp'
'vdbe_listing'
'vdbe_trace'
'where_trace'

Example of usage:
SET full_column_names = true;
SET sql_compound_select_limit(10);
SET sql_default_engine = 'memtx';
---
 src/box/sql/build.c         |  60 +++++++++++++++++++++
 src/box/sql/parse.y         |   8 +++
 src/box/sql/sqlInt.h        |  14 +++++
 test/sql/sql-debug.result   | 127 ++++++++++++++++++++++++++++++++++++++++++++
 test/sql/sql-debug.test.lua |  26 +++++++++
 5 files changed, 235 insertions(+)

diff --git a/src/box/sql/build.c b/src/box/sql/build.c
index 233f567..45bd3c0 100644
--- a/src/box/sql/build.c
+++ b/src/box/sql/build.c
@@ -3241,3 +3241,63 @@ sql_fieldno_by_name(struct Parse *parse_context, struct Expr *field_name,
 	*fieldno = i;
 	return 0;
 }
+
+void
+sql_set_settings(struct Parse *parse_context, struct Token *name,
+		 struct Expr *value)
+{
+	int option_id;
+	struct session *session = current_session();
+	char *name_str = sql_name_from_token(sql_get(), name);
+	if (name_str == NULL) {
+		parse_context->is_aborted = true;
+		return;
+	}
+	for (option_id = 0; option_id < SQL_OPTION_max; ++option_id) {
+		if (strcasecmp(sql_options[option_id].name, name_str) == 0)
+			break;
+	}
+	if (option_id == SQL_OPTION_max) {
+		diag_set(ClientError, ER_SQL_PARSER_GENERIC, "Setting is "
+			 "not found");
+		parse_context->is_aborted = true;
+		return;
+	}
+	struct sql_option_metadata *option = &sql_options[option_id];
+	if (value->type != option->field_type) {
+		diag_set(ClientError, ER_INCONSISTENT_TYPES,
+			 field_type_strs[option->field_type],
+			 field_type_strs[value->type]);
+		parse_context->is_aborted = true;
+		return;
+	}
+	if (value->type == FIELD_TYPE_BOOLEAN) {
+		bool is_set = value->op == TK_TRUE;
+		if (is_set)
+			session->sql_flags |= option->flag;
+		else
+			session->sql_flags &= ~option->flag;
+#ifndef NDEBUG
+		if (option_id == SQL_OPTION_PARSER_TRACE) {
+			if (is_set)
+				sqlParserTrace(stdout, "parser: ");
+			else
+				sqlParserTrace(NULL, NULL);
+		}
+#endif
+	} else if (option_id == SQL_OPTION_DEFAULT_ENGINE) {
+		enum sql_storage_engine engine =
+			STR2ENUM(sql_storage_engine, value->u.zToken);
+		if (engine == sql_storage_engine_MAX) {
+			parse_context->is_aborted = true;
+			diag_set(ClientError, ER_NO_SUCH_ENGINE,
+				 value->u.zToken);
+			return;
+		}
+		current_session()->sql_default_engine = engine;
+	} else {
+		assert(option_id == SQL_OPTION_COMPOUND_SELECT_LIMIT);
+		sql_limit(sql_get(), SQL_LIMIT_COMPOUND_SELECT,
+			  value->u.iValue);
+	}
+}
diff --git a/src/box/sql/parse.y b/src/box/sql/parse.y
index ed59a87..7bea68d 100644
--- a/src/box/sql/parse.y
+++ b/src/box/sql/parse.y
@@ -1535,6 +1535,14 @@ cmd ::= DROP INDEX ifexists(E) nm(X) ON fullname(Y).   {
   sql_drop_index(pParse);
 }
 
+///////////////////////////// The SET command ////////////////////////////////
+cmd ::= SET nm(X) EQ term(Y).  {
+    sql_set_settings(pParse,&X,Y.pExpr);
+}
+cmd ::= SET nm(X) LP term(Y) RP.         {
+    sql_set_settings(pParse,&X,Y.pExpr);
+}
+
 ///////////////////////////// The PRAGMA command /////////////////////////////
 //
 cmd ::= PRAGMA nm(X).                        {
diff --git a/src/box/sql/sqlInt.h b/src/box/sql/sqlInt.h
index a87590e..9a2b5c8 100644
--- a/src/box/sql/sqlInt.h
+++ b/src/box/sql/sqlInt.h
@@ -4436,4 +4436,18 @@ int
 sql_fieldno_by_name(struct Parse *parse_context, struct Expr *field_name,
 		    uint32_t *fieldno);
 
+/**
+ * Set new value for SQL setting.
+ *
+ * @param parse_context Parsing context.
+ * @param name Name of SQL setting to change.
+ * @param value New values of SQL setting.
+ *
+ * @retval 0 on success.
+ * @retval -1 on error.
+ */
+void
+sql_set_settings(struct Parse *parse_context, struct Token *name,
+		 struct Expr *value);
+
 #endif				/* sqlINT_H */
diff --git a/test/sql/sql-debug.result b/test/sql/sql-debug.result
index 2dba684..07542e3 100644
--- a/test/sql/sql-debug.result
+++ b/test/sql/sql-debug.result
@@ -54,3 +54,130 @@ box.execute('PRAGMA')
   - ['vdbe_trace', 0]
   - ['where_trace', 0]
 ...
+--
+-- gh-4511: make sure that SET works.
+--
+box.execute('SELECT "name" FROM "_vsql_settings";')
+---
+- metadata:
+  - name: name
+    type: string
+  rows:
+  - ['defer_foreign_keys']
+  - ['full_column_names']
+  - ['recursive_triggers']
+  - ['reverse_unordered_selects']
+  - ['sql_compound_select_limit']
+  - ['sql_default_engine']
+  - ['parser_trace']
+  - ['select_trace']
+  - ['sql_trace']
+  - ['vdbe_addoptrace']
+  - ['vdbe_debug']
+  - ['vdbe_eqp']
+  - ['vdbe_listing']
+  - ['vdbe_trace']
+  - ['where_trace']
+...
+engine = box.space._vsql_settings:get{'sql_default_engine'}[2]
+---
+...
+order = box.space._vsql_settings:get{'reverse_unordered_selects'}[2]
+---
+...
+box.execute('SET sql_default_engine = 1;')
+---
+- null
+- 'Inconsistent types: expected string got integer'
+...
+box.execute("SET sql_default_engine = 'some_engine';")
+---
+- null
+- Space engine 'some_engine' does not exist
+...
+box.execute("SET engine = 'vinyl';")
+---
+- null
+- Setting is not found
+...
+box.execute("SET defer_foreign_keys('vinyl');")
+---
+- null
+- 'Inconsistent types: expected boolean got string'
+...
+engine == box.space._vsql_settings:get{'sql_default_engine'}[2]
+---
+- true
+...
+order == box.space._vsql_settings:get{'reverse_unordered_selects'}[2]
+---
+- true
+...
+box.execute("SET sql_default_engine = 'vinyl';")
+---
+- row_count: 0
+...
+box.execute("SET reverse_unordered_selects(true);")
+---
+- row_count: 0
+...
+box.execute('SELECT "name" FROM "_vsql_settings";')
+---
+- metadata:
+  - name: name
+    type: string
+  rows:
+  - ['where_trace']
+  - ['vdbe_trace']
+  - ['vdbe_listing']
+  - ['vdbe_eqp']
+  - ['vdbe_debug']
+  - ['vdbe_addoptrace']
+  - ['sql_trace']
+  - ['select_trace']
+  - ['parser_trace']
+  - ['sql_default_engine']
+  - ['sql_compound_select_limit']
+  - ['reverse_unordered_selects']
+  - ['recursive_triggers']
+  - ['full_column_names']
+  - ['defer_foreign_keys']
+...
+box.execute("SET sql_default_engine('memtx');")
+---
+- row_count: 0
+...
+box.execute("SET reverse_unordered_selects = false;")
+---
+- row_count: 0
+...
+box.execute('SELECT "name" FROM "_vsql_settings";')
+---
+- metadata:
+  - name: name
+    type: string
+  rows:
+  - ['defer_foreign_keys']
+  - ['full_column_names']
+  - ['recursive_triggers']
+  - ['reverse_unordered_selects']
+  - ['sql_compound_select_limit']
+  - ['sql_default_engine']
+  - ['parser_trace']
+  - ['select_trace']
+  - ['sql_trace']
+  - ['vdbe_addoptrace']
+  - ['vdbe_debug']
+  - ['vdbe_eqp']
+  - ['vdbe_listing']
+  - ['vdbe_trace']
+  - ['where_trace']
+...
+box.execute("SET sql_default_engine = '"..engine.."';")
+---
+- row_count: 0
+...
+box.execute("SET reverse_unordered_selects = "..tostring(order)..";")
+---
+- row_count: 0
+...
diff --git a/test/sql/sql-debug.test.lua b/test/sql/sql-debug.test.lua
index edd0ef4..60d7fdd 100644
--- a/test/sql/sql-debug.test.lua
+++ b/test/sql/sql-debug.test.lua
@@ -15,3 +15,29 @@ box.execute('PRAGMA parser_trace = '.. result[1][1])
 -- Make PRAGMA command return the result as a result set.
 --
 box.execute('PRAGMA')
+
+--
+-- gh-4511: make sure that SET works.
+--
+box.execute('SELECT "name" FROM "_vsql_settings";')
+
+engine = box.space._vsql_settings:get{'sql_default_engine'}[2]
+order = box.space._vsql_settings:get{'reverse_unordered_selects'}[2]
+
+box.execute('SET sql_default_engine = 1;')
+box.execute("SET sql_default_engine = 'some_engine';")
+box.execute("SET engine = 'vinyl';")
+box.execute("SET defer_foreign_keys('vinyl');")
+engine == box.space._vsql_settings:get{'sql_default_engine'}[2]
+order == box.space._vsql_settings:get{'reverse_unordered_selects'}[2]
+
+box.execute("SET sql_default_engine = 'vinyl';")
+box.execute("SET reverse_unordered_selects(true);")
+box.execute('SELECT "name" FROM "_vsql_settings";')
+
+box.execute("SET sql_default_engine('memtx');")
+box.execute("SET reverse_unordered_selects = false;")
+box.execute('SELECT "name" FROM "_vsql_settings";')
+
+box.execute("SET sql_default_engine = '"..engine.."';")
+box.execute("SET reverse_unordered_selects = "..tostring(order)..";")
-- 
2.7.4