drop table if exists t1,t2; create table t1 (id int not null, f_id int not null, f int not null, primary key(f_id, id)) engine=innodb; create table t2 (id int not null,s_id int not null,s varchar(200), primary key(id)) engine=innodb; INSERT INTO t1 VALUES (8, 1, 3); INSERT INTO t1 VALUES (1, 2, 1); INSERT INTO t2 VALUES (1, 0, ''); INSERT INTO t2 VALUES (8, 1, ''); commit; DELETE ml.* FROM t1 AS ml LEFT JOIN t2 AS mm ON (mm.id=ml.id) WHERE mm.id IS NULL; select ml.* from t1 as ml left join t2 as mm on (mm.id=ml.id) where mm.id is null lock in share mode; id f_id f drop table t1,t2; create table t1(a int not null, b int, primary key(a)) engine=innodb; insert into t1 values(1,1),(2,2),(3,1),(4,2),(5,1),(6,2),(7,3); commit; set autocommit = 0; select * from t1 lock in share mode; a b 1 1 2 2 3 1 4 2 5 1 6 2 7 3 update t1 set b = 5 where b = 1; set autocommit = 0; select * from t1 where a = 2 and b = 2 for update; ERROR HY000: Lock wait timeout exceeded; try restarting transaction commit; commit; drop table t1; create table t1(a int not null, b int, primary key(a)) engine=innodb; insert into t1 values(1,1),(2,2),(3,1),(4,2),(5,1),(6,2),(7,3); commit; set autocommit = 0; update t1 set b = 5 where b = 1; set autocommit = 0; select * from t1 where a = 7 and b = 3 for update; a b 7 3 commit; commit; drop table t1; create table t1(a int not null, b int, primary key(a)) engine=innodb; insert into t1 values (1,2),(5,3),(4,2); create table t2(a int not null, b int, primary key(a)) engine=innodb; insert into t2 values (8,6),(12,1),(3,1); commit; set autocommit = 0; select * from t2 for update; a b 3 1 8 6 12 1 set autocommit = 0; insert into t1 select * from t2; commit; commit; drop table t1, t2; create table t1(a int not null, b int, primary key(a)) engine=innodb; insert into t1 values (1,2),(5,3),(4,2); create table t2(d int not null, e int, primary key(d)) engine=innodb; insert into t2 values (1,6),(5,1),(4,1); commit; set autocommit = 0; select * from t2 for update; d e 1 6 4 1 5 1 set autocommit = 0; update t1 set b = (select e from t2 where a = d); commit; commit; drop table t1, t2; create table t2(a int not null, b int, primary key(a)) engine=innodb; insert into t2 values (1,6),(5,1),(4,1); commit; set autocommit = 0; select * from t2 for update; a b 1 6 4 1 5 1 set autocommit = 0; create table t1(a int not null, b int, primary key(a)) engine=innodb select * from t2; commit; commit; drop table t1, t2; create table t1(a int not null, b int, primary key(a)) engine=innodb; insert into t1 values (1,2),(5,3),(4,2); create table t2(a int not null, b int, primary key(a)) engine=innodb; insert into t2 values (8,6),(12,1),(3,1); commit; set autocommit = 0; select * from t2 for update; a b 3 1 8 6 12 1 set autocommit = 0; SET SESSION TRANSACTION ISOLATION LEVEL SERIALIZABLE; insert into t1 select * from t2; ERROR HY000: Lock wait timeout exceeded; try restarting transaction commit; commit; drop table t1, t2; create table t1(a int not null, b int, primary key(a)) engine=innodb; insert into t1 values (1,2),(5,3),(4,2); create table t2(d int not null, e int, primary key(d)) engine=innodb; insert into t2 values (1,6),(5,1),(4,1); commit; set autocommit = 0; select * from t2 for update; d e 1 6 4 1 5 1 set autocommit = 0; SET SESSION TRANSACTION ISOLATION LEVEL SERIALIZABLE; update t1 set b = (select e from t2 where a = d); ERROR HY000: Lock wait timeout exceeded; try restarting transaction commit; commit; drop table t1, t2; create table t2(a int not null, b int, primary key(a)) engine=innodb; insert into t2 values (1,6),(5,1),(4,1); commit; set autocommit = 0; select * from t2 for update; a b 1 6 4 1 5 1 set autocommit = 0; SET SESSION TRANSACTION ISOLATION LEVEL SERIALIZABLE; create table t1(a int not null, b int, primary key(a)) engine=innodb select * from t2; ERROR HY000: Lock wait timeout exceeded; try restarting transaction commit; commit; drop table t2; create table t1(a int not null, b int, primary key(a)) engine=innodb; insert into t1 values (1,2),(5,3),(4,2); create table t2(a int not null, b int, primary key(a)) engine=innodb; insert into t2 values (8,6),(12,1),(3,1); commit; set autocommit = 0; select * from t2 for update; a b 3 1 8 6 12 1 set autocommit = 0; insert into t1 select * from t2 lock in share mode; ERROR HY000: Lock wait timeout exceeded; try restarting transaction commit; commit; drop table t1, t2; create table t1(a int not null, b int, primary key(a)) engine=innodb; insert into t1 values (1,2),(5,3),(4,2); create table t2(d int not null, e int, primary key(d)) engine=innodb; insert into t2 values (1,6),(5,1),(4,1); commit; set autocommit = 0; select * from t2 for update; d e 1 6 4 1 5 1 set autocommit = 0; update t1 set b = (select e from t2 where a = d lock in share mode); ERROR HY000: Lock wait timeout exceeded; try restarting transaction commit; commit; drop table t1, t2; create table t2(a int not null, b int, primary key(a)) engine=innodb; insert into t2 values (1,6),(5,1),(4,1); commit; set autocommit = 0; select * from t2 for update; a b 1 6 4 1 5 1 set autocommit = 0; create table t1(a int not null, b int, primary key(a)) engine=innodb select * from t2 lock in share mode; ERROR HY000: Lock wait timeout exceeded; try restarting transaction commit; commit; drop table t2; create table t1(a int not null, b int, primary key(a)) engine=innodb; insert into t1 values (1,2),(5,3),(4,2); create table t2(a int not null, b int, primary key(a)) engine=innodb; insert into t2 values (8,6),(12,1),(3,1); commit; set autocommit = 0; select * from t2 for update; a b 3 1 8 6 12 1 set autocommit = 0; insert into t1 select * from t2 for update; ERROR HY000: Lock wait timeout exceeded; try restarting transaction commit; commit; drop table t1, t2; create table t1(a int not null, b int, primary key(a)) engine=innodb; insert into t1 values (1,2),(5,3),(4,2); create table t2(d int not null, e int, primary key(d)) engine=innodb; insert into t2 values (1,6),(5,1),(4,1); commit; set autocommit = 0; select * from t2 for update; d e 1 6 4 1 5 1 set autocommit = 0; update t1 set b = (select e from t2 where a = d for update); ERROR HY000: Lock wait timeout exceeded; try restarting transaction commit; commit; drop table t1, t2; create table t2(a int not null, b int, primary key(a)) engine=innodb; insert into t2 values (1,6),(5,1),(4,1); commit; set autocommit = 0; select * from t2 for update; a b 1 6 4 1 5 1 set autocommit = 0; create table t1(a int not null, b int, primary key(a)) engine=innodb select * from t2 for update; ERROR HY000: Lock wait timeout exceeded; try restarting transaction commit; commit; drop table t2;