executor: execute some statement (create user grant etc) would co…

…mmit current transaction automically (#10739)

executor/grant.go

@@ -64,7 +64,7 @@ func (e *GrantExec) Next(ctx context.Context, chk *chunk.Chunk) error {
 		dbName = e.ctx.GetSessionVars().CurrentDB
 	}
 	// Grant for each user
-	for _, user := range e.Users {
+	for idx, user := range e.Users {
 		// Check if user exists.
 		exists, err := userExists(e.ctx, user.User.Username, user.User.Hostname)
 		if err != nil {
@@ -103,6 +103,15 @@ func (e *GrantExec) Next(ctx context.Context, chk *chunk.Chunk) error {
 		if e.WithGrant {
 			privs = append(privs, &ast.PrivElem{Priv: mysql.GrantPriv})
 		}
+
+		if idx == 0 {
+			// Commit the old transaction, like DDL.
+			if err := e.ctx.NewTxn(); err != nil {
+				return err
+			}
+			defer func() { e.ctx.GetSessionVars().SetStatusFlag(mysql.ServerStatusInTrans, false) }()
+		}
+
 		// Grant each priv to the user.
 		for _, priv := range privs {
 			if len(priv.Cols) > 0 {

executor/revoke.go

@@ -58,7 +58,7 @@ func (e *RevokeExec) Next(ctx context.Context, chk *chunk.Chunk) error {
 	e.done = true
 
 	// Revoke for each user.
-	for _, user := range e.Users {
+	for idx, user := range e.Users {
 		// Check if user exists.
 		exists, err := userExists(e.ctx, user.User.Username, user.User.Hostname)
 		if err != nil {
@@ -68,6 +68,13 @@ func (e *RevokeExec) Next(ctx context.Context, chk *chunk.Chunk) error {
 			return errors.Errorf("Unknown user: %s", user.User)
 		}
 
+		if idx == 0 {
+			// Commit the old transaction, like DDL.
+			if err := e.ctx.NewTxn(); err != nil {
+				return err
+			}
+			defer func() { e.ctx.GetSessionVars().SetStatusFlag(mysql.ServerStatusInTrans, false) }()
+		}
 		err = e.revokeOneUser(user.User.Username, user.User.Hostname)
 		if err != nil {
 			return errors.Trace(err)

executor/simple.go

@@ -54,6 +54,15 @@ func (e *SimpleExec) Next(ctx context.Context, chk *chunk.Chunk) (err error) {
 	if e.done {
 		return nil
 	}
+
+	if e.autoNewTxn() {
+		// Commit the old transaction, like DDL.
+		if err := e.ctx.NewTxn(); err != nil {
+			return err
+		}
+		defer func() { e.ctx.GetSessionVars().SetStatusFlag(mysql.ServerStatusInTrans, false) }()
+	}
+
 	switch x := e.Statement.(type) {
 	case *ast.UseStmt:
 		err = e.executeUse(x)
@@ -66,7 +75,7 @@ func (e *SimpleExec) Next(ctx context.Context, chk *chunk.Chunk) (err error) {
 	case *ast.RollbackStmt:
 		err = e.executeRollback(x)
 	case *ast.CreateUserStmt:
-		err = e.executeCreateUser(x)
+		err = e.executeCreateUser(ctx, x)
 	case *ast.AlterUserStmt:
 		err = e.executeAlterUser(x)
 	case *ast.DropUserStmt:
@@ -141,7 +150,7 @@ func (e *SimpleExec) executeRollback(s *ast.RollbackStmt) error {
 	return nil
 }
 
-func (e *SimpleExec) executeCreateUser(s *ast.CreateUserStmt) error {
+func (e *SimpleExec) executeCreateUser(ctx context.Context, s *ast.CreateUserStmt) error {
 	users := make([]string, 0, len(s.Specs))
 	for _, spec := range s.Specs {
 		exists, err1 := userExists(e.ctx, spec.User.Username, spec.User.Hostname)
@@ -164,6 +173,7 @@ func (e *SimpleExec) executeCreateUser(s *ast.CreateUserStmt) error {
 	if len(users) == 0 {
 		return nil
 	}
+
 	sql := fmt.Sprintf(`INSERT INTO %s.%s (Host, User, Password) VALUES %s;`, mysql.SystemDB, mysql.UserTable, strings.Join(users, ", "))
 	_, err := e.ctx.(sqlexec.SQLExecutor).Execute(context.Background(), sql)
 	if err != nil {
@@ -370,3 +380,11 @@ func (e *SimpleExec) executeDropStats(s *ast.DropStatsStmt) error {
 	}
 	return errors.Trace(h.Update(GetInfoSchema(e.ctx)))
 }
+
+func (e *SimpleExec) autoNewTxn() bool {
+	switch e.Statement.(type) {
+	case *ast.CreateUserStmt, *ast.AlterUserStmt, *ast.DropUserStmt:
+		return true
+	}
+	return false
+}

executor/simple_test.go

@@ -296,3 +296,33 @@ func (s *testSuite) TestDropStats(c *C) {
 	c.Assert(statsTbl.Pseudo, IsTrue)
 	h.Lease = 0
 }
+
+func (s *testSuite) TestStmtAutoNewTxn(c *C) {
+	// Some statements are like DDL, they commit the previous txn automically.
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec("use test")
+
+	// Fix issue https://github.com/pingcap/tidb/issues/10705
+	tk.MustExec("begin")
+	tk.MustExec("create user 'xxx'@'%';")
+	tk.MustExec("grant all privileges on *.* to 'xxx'@'%';")
+
+	tk.MustExec("create table auto_new (id int)")
+	tk.MustExec("begin")
+	tk.MustExec("insert into auto_new values (1)")
+	tk.MustExec("revoke all privileges on *.* from 'xxx'@'%'")
+	tk.MustExec("rollback") // insert statement has already committed
+	tk.MustQuery("select * from auto_new").Check(testkit.Rows("1"))
+
+	// Test the behavior when autocommit is false.
+	tk.MustExec("set autocommit = 0")
+	tk.MustExec("insert into auto_new values (2)")
+	tk.MustExec("create user 'yyy'@'%'")
+	tk.MustExec("rollback")
+	tk.MustQuery("select * from auto_new").Check(testkit.Rows("1", "2"))
+
+	tk.MustExec("drop user 'yyy'@'%'")
+	tk.MustExec("insert into auto_new values (3)")
+	tk.MustExec("rollback")
+	tk.MustQuery("select * from auto_new").Check(testkit.Rows("1", "2"))
+}