planner: Do not allow variables in create view

errors.toml

@@ -901,6 +901,11 @@ error = '''
 View's SELECT contains a '%s' clause
 '''
 
+["ddl:1351"]
+error = '''
+View's SELECT contains a variable or parameter
+'''
+
 ["ddl:1353"]
 error = '''
 In definition of view, derived table or common table expression, SELECT list and column names list have different column counts

pkg/planner/core/planbuilder.go

@@ -4928,6 +4928,32 @@ func convertValueListToData(valueList []ast.ExprNode, handleColInfos []*model.Co
 	return data, nil
 }
 
+type userVariableChecker struct {
+	hasUserVariables bool
+}
+
+func (e *userVariableChecker) Enter(in ast.Node) (ast.Node, bool) {
+	if _, ok := in.(*ast.VariableExpr); ok {
+		e.hasUserVariables = true
+		return in, true
+	}
+	return in, false
+}
+
+func (*userVariableChecker) Leave(in ast.Node) (ast.Node, bool) {
+	return in, true
+}
+
+// Check for UserVariables
+func checkForUserVariables(in ast.Node) error {
+	v := &userVariableChecker{hasUserVariables: false}
+	_, ok := in.Accept(v)
+	if !ok || v.hasUserVariables {
+		return dbterror.ErrViewSelectVariable
+	}
+	return nil
+}
+
 func (b *PlanBuilder) buildDDL(ctx context.Context, node ast.DDLNode) (base.Plan, error) {
 	var authErr error
 	switch v := node.(type) {
@@ -5075,6 +5101,10 @@ func (b *PlanBuilder) buildDDL(ctx context.Context, node ast.DDLNode) (base.Plan
 				v.ReferTable.Name.L, "", authErr)
 		}
 	case *ast.CreateViewStmt:
+		err := checkForUserVariables(v.Select)
+		if err != nil {
+			return nil, err
+		}
 		b.isCreateView = true
 		b.capFlag |= canExpandAST | renameView
 		b.renamingViewName = v.ViewName.Schema.L + "." + v.ViewName.Name.L

pkg/util/dbterror/ddl_terror.go

@@ -229,6 +229,8 @@ var (
 	ErrErrorOnRename = ClassDDL.NewStd(mysql.ErrErrorOnRename)
 	// ErrViewSelectClause returns error for create view with select into clause
 	ErrViewSelectClause = ClassDDL.NewStd(mysql.ErrViewSelectClause)
+	// ErrViewSelectVariable returns error for create view with select into clause
+	ErrViewSelectVariable = ClassDDL.NewStd(mysql.ErrViewSelectVariable)
 
 	// ErrNotAllowedTypeInPartition returns not allowed type error when creating table partition with unsupported expression type.
 	ErrNotAllowedTypeInPartition = ClassDDL.NewStd(mysql.ErrFieldTypeNotAllowedAsPartitionField)

tests/integrationtest/r/ddl/ddl_error.result

@@ -11,3 +11,11 @@ Error 1450 (HY000): Changing schema from 'ddl__ddl_error' to 'ddl__ddl_error2' i
 rename table ddl__ddl_error.view_1 to ddl__ddl_error2.view_1;
 Error 1450 (HY000): Changing schema from 'ddl__ddl_error' to 'ddl__ddl_error2' is not allowed.
 rename table ddl__ddl_error.view_1 to ddl__ddl_error.view_1000;
+create view sql_mode_view as select @@sql_mode;
+Error 1351 (HY000): View's SELECT contains a variable or parameter
+create view sql_mode_view as select @@global.sql_mode;
+Error 1351 (HY000): View's SELECT contains a variable or parameter
+create view sql_mode_view as select @a;
+Error 1351 (HY000): View's SELECT contains a variable or parameter
+create view sql_mode_view as select 1 where @a = 4;
+Error 1351 (HY000): View's SELECT contains a variable or parameter

tests/integrationtest/r/executor/ddl.result

@@ -314,9 +314,9 @@ create view v7 (c,d,e) as select * from t1;
 Error 1353 (HY000): In definition of view, derived table or common table expression, SELECT list and column names list have different column counts
 drop view v1,v2,v3,v4,v5,v6;
 create view v1 (c,d) as select a,b+@@global.max_user_connections from t1;
+Error 1351 (HY000): View's SELECT contains a variable or parameter
 create view v1 (c,d) as select a,b from t1 where a = @@global.max_user_connections;
-Error 1050 (42S01): Table 'executor__ddl.v1' already exists
-drop view v1;
+Error 1351 (HY000): View's SELECT contains a variable or parameter
 create view v1 (c,d,e) as select a,b from t1 ;
 Error 1353 (HY000): In definition of view, derived table or common table expression, SELECT list and column names list have different column counts
 create view v1 (c) as select a,b from t1 ;

tests/integrationtest/t/ddl/ddl_error.test

@@ -13,3 +13,12 @@ rename table ddl__ddl_error.view_1 to ddl__ddl_error2.view_1;
 rename table ddl__ddl_error.view_1 to ddl__ddl_error2.view_1;
 rename table ddl__ddl_error.view_1 to ddl__ddl_error.view_1000;
 
+# issue 53176
+-- error 1351
+create view sql_mode_view as select @@sql_mode;
+-- error 1351
+create view sql_mode_view as select @@global.sql_mode;
+-- error 1351
+create view sql_mode_view as select @a;
+-- error 1351
+create view sql_mode_view as select 1 where @a = 4;

tests/integrationtest/t/executor/ddl.test

@@ -258,10 +258,10 @@ create view v6 (c,d) as select * from t1;
 -- error 1353
 create view v7 (c,d,e) as select * from t1;
 drop view v1,v2,v3,v4,v5,v6;
+-- error 1351
 create view v1 (c,d) as select a,b+@@global.max_user_connections from t1;
--- error 1050
+-- error 1351
 create view v1 (c,d) as select a,b from t1 where a = @@global.max_user_connections;
-drop view v1;
 -- error 1353
 create view v1 (c,d,e) as select a,b from t1 ;
 -- error 1353