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drop table if exists t1,t2,t3;
create table t1(id1 int not null auto_increment primary key, t char(12));
create table t2(id2 int not null, t char(12));
create table t3(id3 int not null, t char(12), index(id3));
select count(*) from t1 where id1 > 95;
count(*)
5
select count(*) from t2 where id2 > 95;
count(*)
25
select count(*) from t3 where id3 > 95;
count(*)
250
update t1,t2,t3 set t1.t="aaa", t2.t="bbb", t3.t="cc" where t1.id1 = t2.id2 and t2.id2 = t3.id3 and t1.id1 > 90;
select count(*) from t1 where t = "aaa";
count(*)
10
select count(*) from t1 where id1 > 90;
count(*)
10
select count(*) from t2 where t = "bbb";
count(*)
10
select count(*) from t2 where id2 > 90;
count(*)
50
select count(*) from t3 where t = "cc";
count(*)
500
select count(*) from t3 where id3 > 90;
count(*)
500
delete t1.*, t2.*, t3.* from t1,t2,t3 where t1.id1 = t2.id2 and t2.id2 = t3.id3 and t1.id1 > 95;
check table t1, t2, t3;
Table Op Msg_type Msg_text
test.t1 check status OK
test.t2 check status OK
test.t3 check status OK
select count(*) from t1 where id1 > 95;
count(*)
0
select count(*) from t2 where id2 > 95;
count(*)
0
select count(*) from t3 where id3 > 95;
count(*)
0
delete t1, t2, t3 from t1,t2,t3 where t1.id1 = t2.id2 and t2.id2 = t3.id3 and t1.id1 > 5;
select count(*) from t1 where id1 > 5;
count(*)
0
select count(*) from t2 where id2 > 5;
count(*)
0
select count(*) from t3 where id3 > 5;
count(*)
0
delete from t1, t2, t3 using t1,t2,t3 where t1.id1 = t2.id2 and t2.id2 = t3.id3 and t1.id1 > 0;
select count(*) from t1 where id1;
count(*)
0
select count(*) from t2 where id2;
count(*)
0
select count(*) from t3 where id3;
count(*)
0
drop table t1,t2,t3;
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