ddl: forbid truncating sequence object (#16981)

ddl/db_test.go

@@ -4248,12 +4248,19 @@ func (s *testDBSuite2) TestLockTables(c *C) {
 	_, err = tk.Exec("create view v1 as select * from t1;")
 	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableNotLocked), IsTrue)
 
-	// Test for lock view was not supported.
+	// Test for locking view was not supported.
 	tk.MustExec("unlock tables")
 	tk.MustExec("create view v1 as select * from t1;")
 	_, err = tk.Exec("lock tables v1 read")
 	c.Assert(terror.ErrorEqual(err, table.ErrUnsupportedOp), IsTrue)
 
+	// Test for locking sequence was not supported.
+	tk.MustExec("unlock tables")
+	tk.MustExec("create sequence seq")
+	_, err = tk.Exec("lock tables seq read")
+	c.Assert(terror.ErrorEqual(err, table.ErrUnsupportedOp), IsTrue)
+	tk.MustExec("drop sequence seq")
+
 	// Test for create/drop/alter database when session is holding the table locks.
 	tk.MustExec("unlock tables")
 	tk.MustExec("lock table t1 write")

ddl/ddl_api.go

@@ -3565,6 +3565,9 @@ func (d *ddl) TruncateTable(ctx sessionctx.Context, ti ast.Ident) error {
 	if err != nil {
 		return errors.Trace(err)
 	}
+	if tb.Meta().IsView() || tb.Meta().IsSequence() {
+		return infoschema.ErrTableNotExists.GenWithStackByArgs(schema.Name.O, tb.Meta().Name.O)
+	}
 	genIDs, err := d.genGlobalIDs(1)
 	if err != nil {
 		return errors.Trace(err)
@@ -4260,7 +4263,7 @@ func (d *ddl) LockTables(ctx sessionctx.Context, stmt *ast.LockTablesStmt) error
 		if err != nil {
 			return errors.Trace(err)
 		}
-		if t.Meta().IsView() {
+		if t.Meta().IsView() || t.Meta().IsSequence() {
 			return table.ErrUnsupportedOp.GenWithStackByArgs()
 		}
 		err = checkTableLocked(t.Meta(), tl.Type, sessionInfo)
@@ -4350,7 +4353,7 @@ func (d *ddl) CleanupTableLock(ctx sessionctx.Context, tables []*ast.TableName)
 		if err != nil {
 			return errors.Trace(err)
 		}
-		if t.Meta().IsView() {
+		if t.Meta().IsView() || t.Meta().IsSequence() {
 			return table.ErrUnsupportedOp
 		}
 		// Maybe the table t was not locked, but still try to unlock this table.

ddl/table.go

@@ -430,7 +430,7 @@ func onTruncateTable(d *ddlCtx, t *meta.Meta, job *model.Job) (ver int64, _ erro
 	if err != nil {
 		return ver, errors.Trace(err)
 	}
-	if tblInfo.IsView() {
+	if tblInfo.IsView() || tblInfo.IsSequence() {
 		job.State = model.JobStateCancelled
 		return ver, infoschema.ErrTableNotExists.GenWithStackByArgs(job.SchemaName, tblInfo.Name.O)
 	}

executor/ddl_test.go

@@ -287,6 +287,19 @@ func (s *testSuite6) TestIssue16250(c *C) {
 	c.Assert(err.Error(), Equals, "[schema:1146]Table 'test.view_issue16250' doesn't exist")
 }
 
+func (s testSuite6) TestTruncateSequence(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec("use test")
+	tk.MustExec("create sequence if not exists seq")
+	_, err := tk.Exec("truncate table seq")
+	c.Assert(err.Error(), Equals, "[schema:1146]Table 'test.seq' doesn't exist")
+	tk.MustExec("create sequence if not exists seq1 start 10 increment 2 maxvalue 10000 cycle")
+	_, err = tk.Exec("truncate table seq1")
+	c.Assert(err.Error(), Equals, "[schema:1146]Table 'test.seq1' doesn't exist")
+	tk.MustExec("drop sequence if exists seq")
+	tk.MustExec("drop sequence if exists seq1")
+}
+
 func (s *testSuite6) TestCreateViewWithOverlongColName(c *C) {
 	tk := testkit.NewTestKit(c, s.store)
 	tk.MustExec("use test")