CREATE TABLE t1 ( `id` int(11) NOT NULL default '0', `id2` int(11) NOT NULL default '0', `id3` int(11) NOT NULL default '0', `dummy1` char(30) default NULL, PRIMARY KEY (`id`,`id2`), KEY `index_id3` (`id3`)) ENGINE=MyISAM; Warnings: Warning 1681 Integer display width is deprecated and will be removed in a future release. Warning 1681 Integer display width is deprecated and will be removed in a future release. Warning 1681 Integer display width is deprecated and will be removed in a future release. insert into t1 (id,id2) values (1,1),(1,2),(1,3); LOCK TABLE t1 WRITE; select dummy1,count(distinct id) from t1 group by dummy1; dummy1 count(distinct id) NULL 1 update t1 set id=-1 where id=1; LOCK TABLE t1 READ; update t1 set id=1 where id=1; ERROR HY000: Table 't1' was locked with a READ lock and can't be updated create table t2 SELECT * from t1; ERROR HY000: Table 't2' was not locked with LOCK TABLES create temporary table t2 SELECT * from t1; drop table if exists t2; unlock tables; create table t2 SELECT * from t1; LOCK TABLE t1 WRITE,t2 write; insert into t2 SELECT * from t1; update t1 set id=1 where id=-1; drop table t1,t2; CREATE TABLE t1 ( index1 smallint(6) default NULL, nr smallint(6) default NULL, KEY index1(index1) ) ENGINE=MyISAM; Warnings: Warning 1681 Integer display width is deprecated and will be removed in a future release. Warning 1681 Integer display width is deprecated and will be removed in a future release. CREATE TABLE t2 ( nr smallint(6) default NULL, name varchar(20) default NULL ) ENGINE=MyISAM; Warnings: Warning 1681 Integer display width is deprecated and will be removed in a future release. INSERT INTO t2 VALUES (1,'item1'); INSERT INTO t2 VALUES (2,'item2'); lock tables t1 write, t2 read; insert into t1 select 1,nr from t2 where name='item1'; insert into t1 select 2,nr from t2 where name='item2'; unlock tables; check table t1; Table Op Msg_type Msg_text test.t1 check status OK lock tables t1 write; check table t2; Table Op Msg_type Msg_text test.t2 check Error Table 't2' was not locked with LOCK TABLES test.t2 check status Operation failed insert into t1 select index1,nr from t1; ERROR HY000: Table 't1' was not locked with LOCK TABLES unlock tables; lock tables t1 write, t1 as t1_alias read; insert into t1 select index1,nr from t1 as t1_alias; drop table t1,t2; ERROR HY000: Table 't2' was not locked with LOCK TABLES unlock tables; drop table t1,t2; # # Ensure that REPAIR .. USE_FRM works under LOCK TABLES. # create table t1 (a int) engine=myisam; create table t2 (a int) engine=myisam; lock table t1 write, t2 write; repair table t1 use_frm; Table Op Msg_type Msg_text test.t1 repair status OK repair table t1 use_frm; Table Op Msg_type Msg_text test.t1 repair status OK select * from t1; a select * from t2; a repair table t2 use_frm; Table Op Msg_type Msg_text test.t2 repair status OK repair table t2 use_frm; Table Op Msg_type Msg_text test.t2 repair status OK select * from t1; a unlock tables; drop table t1, t2; # # Additional test coverage for WL#5534 - Online ALTER phase 1. # CREATE TABLE t1(a INT) ENGINE = MYISAM; CREATE TABLE m1(a INT) engine=merge union(t1); LOCK TABLES m1 WRITE; ALTER TABLE m1 COMMENT 'test'; # This triggered an assert in MDL_ticket::downgrade_lock FLUSH TABLE m1; UNLOCK TABLES; DROP TABLE m1, t1;