create table t1 (old_c1 integer, old_c2 integer,c1 integer, c2 integer, c3 integer) engine=InnoDb;
create view v1 as select * from t1 where c2=2;
create trigger trg_t1 before update on t1 for each row
begin
set new.old_c1=old.c1;
set new.old_c2=old.c2;
end;
/
insert into t1(c1,c2,c3) values (1,1,1);
insert into t1(c1,c2,c3) values (1,2,2);
insert into t1(c1,c2,c3) values (1,3,3);
insert into t1(c1,c2,c3) values (2,1,4);
insert into t1(c1,c2,c3) values (2,2,5);
insert into t1(c1,c2,c3) values (2,3,6);
insert into t1(c1,c2,c3) values (2,4,7);
insert into t1(c1,c2,c3) values (2,5,8);
commit;
select * from t1;
old_c1	old_c2	c1	c2	c3
NULL	NULL	1	1	1
NULL	NULL	1	2	2
NULL	NULL	1	3	3
NULL	NULL	2	1	4
NULL	NULL	2	2	5
NULL	NULL	2	3	6
NULL	NULL	2	4	7
NULL	NULL	2	5	8
Test without any index
#
# Update a with value from subquery on the same table, no search clause. ALL access
#
start transaction;
update t1
set c1=(select a.c3
from t1 a
where a.c3 = t1.c3);
affected rows: 8
info: Rows matched: 8  Changed: 8  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1 ;
concat(old_c1,'->',c1)	c3	Changed
1->1	1	 
1->2	2	*
1->3	3	*
2->4	4	*
2->5	5	*
2->6	6	*
2->7	7	*
2->8	8	*
rollback;
#
# Update with search clause on the same table
#
start transaction;
update t1
set c1=10
where c1 <2
and exists (select 'X'
                 from t1 a
where a.c1 = t1.c1);
affected rows: 3
info: Rows matched: 3  Changed: 3  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1 ;
concat(old_c1,'->',c1)	c3	Changed
1->10	1	*
1->10	2	*
1->10	3	*
NULL	4	 
NULL	5	 
NULL	6	 
NULL	7	 
NULL	8	 
rollback;
#
# Update via RANGE or INDEX access if an index or a primary key exists
#
explain update t1 set c1=0 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 > 3;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	8	Using where
2	DEPENDENT SUBQUERY	a	ALL	NULL	NULL	NULL	NULL	8	Using where
start transaction;
update t1 set c1=c1+10 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 >= 3;
affected rows: 4
info: Rows matched: 4  Changed: 4  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1;
concat(old_c1,'->',c1)	c3	Changed
NULL	1	 
NULL	2	 
1->11	3	*
NULL	4	 
NULL	5	 
2->12	6	*
2->12	7	*
2->12	8	*
rollback;
#
# Update with order by
#
start transaction;
update t1 set c1=c1+10 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 >= 3 order by c2;
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1;
concat(old_c1,'->',c1)	c3	Changed
NULL	1	 
NULL	2	 
1->11	3	*
NULL	4	 
NULL	5	 
2->12	6	*
2->12	7	*
2->12	8	*
rollback;
#
Update using a view in subquery
#
start transaction;
update t1
set c1=c1 +(select max(a.c2)
from v1 a
where a.c1 = t1.c1) ;
affected rows: 8
info: Rows matched: 8  Changed: 8  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1;
concat(old_c1,'->',c1)	c3	Changed
1->3	1	*
1->3	2	*
1->3	3	*
2->4	4	*
2->4	5	*
2->4	6	*
2->4	7	*
2->4	8	*
rollback;
#
# Update throw a view
#
start transaction;
update v1
set c1=c1 + (select max(a.c2)
from t1 a
where a.c1 = v1.c1) +10
where c3 > 3;
affected rows: 1
info: Rows matched: 1  Changed: 1  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1;
concat(old_c1,'->',c1)	c3	Changed
NULL	1	 
NULL	2	 
NULL	3	 
NULL	4	 
2->17	5	*
NULL	6	 
NULL	7	 
NULL	8	 
rollback;
#
# Update through a view and using the view in subquery
#
start transaction;
update v1
set c1=c1 + 1
where c1 <2
and exists (select 'X'
                 from v1 a
where a.c1 = v1.c1);
affected rows: 1
info: Rows matched: 1  Changed: 1  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1;
concat(old_c1,'->',c1)	c3	Changed
NULL	1	 
1->2	2	*
NULL	3	 
NULL	4	 
NULL	5	 
NULL	6	 
NULL	7	 
NULL	8	 
rollback;
#
# Update through  a view and using the view in subquery
#
start transaction;
update v1
set c1=(select max(a.c1)+10
from v1 a
where a.c1 = v1.c1)
where c1 <10
and exists (select 'X'
                 from v1 a
where a.c2 = v1.c2);
affected rows: 2
info: Rows matched: 2  Changed: 2  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1;
concat(old_c1,'->',c1)	c3	Changed
NULL	1	 
1->11	2	*
NULL	3	 
NULL	4	 
2->12	5	*
NULL	6	 
NULL	7	 
NULL	8	 
rollback;
#
# Update of the index or primary key (c3)
#
start transaction;
explain update t1 set c3=c3+10 where c2 in (select distinct a.c2 from t1 a where t1.c1=a.c1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	8	
1	PRIMARY	a	ALL	NULL	NULL	NULL	NULL	8	Using where; FirstMatch(t1)
update t1 set c3=c3+10 where c2 in (select distinct a.c2 from t1 a where t1.c1=a.c1);
affected rows: 8
info: Rows matched: 8  Changed: 8  Warnings: 0
select c3 from t1;
c3
11
12
13
14
15
16
17
18
rollback;
#
# update with a limit
#
start transaction;
update t1
set c1=(select a.c3
from t1 a
where a.c3 = t1.c3)
limit 2;
affected rows: 2
info: Rows matched: 2  Changed: 2  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1 ;
concat(old_c1,'->',c1)	c3	Changed
1->1	1	 
1->2	2	*
NULL	3	 
NULL	4	 
NULL	5	 
NULL	6	 
NULL	7	 
NULL	8	 
rollback;
#
# update with a limit and an order by
#
start transaction;
update t1
set c1=(select a.c3
from t1 a
where a.c3 = t1.c3)
order by c3 desc limit 2;
affected rows: 2
info: Rows matched: 2  Changed: 2  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1 ;
concat(old_c1,'->',c1)	c3	Changed
NULL	1	 
NULL	2	 
NULL	3	 
NULL	4	 
NULL	5	 
NULL	6	 
2->7	7	*
2->8	8	*
rollback;
Test with an index on updated columns
create index t1_c2 on t1 (c2,c1);
#
# Update a with value from subquery on the same table, no search clause. ALL access
#
start transaction;
update t1
set c1=(select a.c3
from t1 a
where a.c3 = t1.c3);
affected rows: 8
info: Rows matched: 8  Changed: 8  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1 ;
concat(old_c1,'->',c1)	c3	Changed
1->1	1	 
1->2	2	*
1->3	3	*
2->4	4	*
2->5	5	*
2->6	6	*
2->7	7	*
2->8	8	*
rollback;
#
# Update with search clause on the same table
#
start transaction;
update t1
set c1=10
where c1 <2
and exists (select 'X'
                 from t1 a
where a.c1 = t1.c1);
affected rows: 3
info: Rows matched: 3  Changed: 3  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1 ;
concat(old_c1,'->',c1)	c3	Changed
1->10	1	*
1->10	2	*
1->10	3	*
NULL	4	 
NULL	5	 
NULL	6	 
NULL	7	 
NULL	8	 
rollback;
#
# Update via RANGE or INDEX access if an index or a primary key exists
#
explain update t1 set c1=0 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 > 3;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1	range	t1_c2	t1_c2	5	NULL	2	Using where
2	DEPENDENT SUBQUERY	a	ref	t1_c2	t1_c2	5	test.t1.c2	4	Using index
start transaction;
update t1 set c1=c1+10 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 >= 3;
affected rows: 4
info: Rows matched: 4  Changed: 4  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1;
concat(old_c1,'->',c1)	c3	Changed
NULL	1	 
NULL	2	 
1->11	3	*
NULL	4	 
NULL	5	 
2->12	6	*
2->12	7	*
2->12	8	*
rollback;
#
# Update with order by
#
start transaction;
update t1 set c1=c1+10 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 >= 3 order by c2;
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1;
concat(old_c1,'->',c1)	c3	Changed
NULL	1	 
NULL	2	 
1->11	3	*
NULL	4	 
NULL	5	 
2->12	6	*
2->12	7	*
2->12	8	*
rollback;
#
Update using a view in subquery
#
start transaction;
update t1
set c1=c1 +(select max(a.c2)
from v1 a
where a.c1 = t1.c1) ;
affected rows: 8
info: Rows matched: 8  Changed: 8  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1;
concat(old_c1,'->',c1)	c3	Changed
1->3	1	*
1->3	2	*
1->3	3	*
2->4	4	*
2->4	5	*
2->4	6	*
2->4	7	*
2->4	8	*
rollback;
#
# Update throw a view
#
start transaction;
update v1
set c1=c1 + (select max(a.c2)
from t1 a
where a.c1 = v1.c1) +10
where c3 > 3;
affected rows: 1
info: Rows matched: 1  Changed: 1  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1;
concat(old_c1,'->',c1)	c3	Changed
NULL	1	 
NULL	2	 
NULL	3	 
NULL	4	 
2->17	5	*
NULL	6	 
NULL	7	 
NULL	8	 
rollback;
#
# Update through a view and using the view in subquery
#
start transaction;
update v1
set c1=c1 + 1
where c1 <2
and exists (select 'X'
                 from v1 a
where a.c1 = v1.c1);
affected rows: 1
info: Rows matched: 1  Changed: 1  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1;
concat(old_c1,'->',c1)	c3	Changed
NULL	1	 
1->2	2	*
NULL	3	 
NULL	4	 
NULL	5	 
NULL	6	 
NULL	7	 
NULL	8	 
rollback;
#
# Update through  a view and using the view in subquery
#
start transaction;
update v1
set c1=(select max(a.c1)+10
from v1 a
where a.c1 = v1.c1)
where c1 <10
and exists (select 'X'
                 from v1 a
where a.c2 = v1.c2);
affected rows: 2
info: Rows matched: 2  Changed: 2  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1;
concat(old_c1,'->',c1)	c3	Changed
NULL	1	 
1->11	2	*
NULL	3	 
NULL	4	 
2->12	5	*
NULL	6	 
NULL	7	 
NULL	8	 
rollback;
#
# Update of the index or primary key (c3)
#
start transaction;
explain update t1 set c3=c3+10 where c2 in (select distinct a.c2 from t1 a where t1.c1=a.c1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1	ALL	t1_c2	NULL	NULL	NULL	8	Using where
1	PRIMARY	a	ref	t1_c2	t1_c2	10	test.t1.c2,test.t1.c1	1	Using index; FirstMatch(t1)
update t1 set c3=c3+10 where c2 in (select distinct a.c2 from t1 a where t1.c1=a.c1);
affected rows: 8
info: Rows matched: 8  Changed: 8  Warnings: 0
select c3 from t1;
c3
11
12
13
14
15
16
17
18
rollback;
#
# update with a limit
#
start transaction;
update t1
set c1=(select a.c3
from t1 a
where a.c3 = t1.c3)
limit 2;
affected rows: 2
info: Rows matched: 2  Changed: 2  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1 ;
concat(old_c1,'->',c1)	c3	Changed
1->1	1	 
1->2	2	*
NULL	3	 
NULL	4	 
NULL	5	 
NULL	6	 
NULL	7	 
NULL	8	 
rollback;
#
# update with a limit and an order by
#
start transaction;
update t1
set c1=(select a.c3
from t1 a
where a.c3 = t1.c3)
order by c3 desc limit 2;
affected rows: 2
info: Rows matched: 2  Changed: 2  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1 ;
concat(old_c1,'->',c1)	c3	Changed
NULL	1	 
NULL	2	 
NULL	3	 
NULL	4	 
NULL	5	 
NULL	6	 
2->7	7	*
2->8	8	*
rollback;
Test with an index on updated columns
create index t1_c3 on t1 (c3);
#
# Update a with value from subquery on the same table, no search clause. ALL access
#
start transaction;
update t1
set c1=(select a.c3
from t1 a
where a.c3 = t1.c3);
affected rows: 8
info: Rows matched: 8  Changed: 8  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1 ;
concat(old_c1,'->',c1)	c3	Changed
1->1	1	 
1->2	2	*
1->3	3	*
2->4	4	*
2->5	5	*
2->6	6	*
2->7	7	*
2->8	8	*
rollback;
#
# Update with search clause on the same table
#
start transaction;
update t1
set c1=10
where c1 <2
and exists (select 'X'
                 from t1 a
where a.c1 = t1.c1);
affected rows: 3
info: Rows matched: 3  Changed: 3  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1 ;
concat(old_c1,'->',c1)	c3	Changed
1->10	1	*
1->10	2	*
1->10	3	*
NULL	4	 
NULL	5	 
NULL	6	 
NULL	7	 
NULL	8	 
rollback;
#
# Update via RANGE or INDEX access if an index or a primary key exists
#
explain update t1 set c1=0 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 > 3;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1	range	t1_c2	t1_c2	5	NULL	2	Using where
2	DEPENDENT SUBQUERY	a	ref	t1_c2	t1_c2	5	test.t1.c2	1	Using index
start transaction;
update t1 set c1=c1+10 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 >= 3;
affected rows: 4
info: Rows matched: 4  Changed: 4  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1;
concat(old_c1,'->',c1)	c3	Changed
NULL	1	 
NULL	2	 
1->11	3	*
NULL	4	 
NULL	5	 
2->12	6	*
2->12	7	*
2->12	8	*
rollback;
#
# Update with order by
#
start transaction;
update t1 set c1=c1+10 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 >= 3 order by c2;
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1;
concat(old_c1,'->',c1)	c3	Changed
NULL	1	 
NULL	2	 
1->11	3	*
NULL	4	 
NULL	5	 
2->12	6	*
2->12	7	*
2->12	8	*
rollback;
#
Update using a view in subquery
#
start transaction;
update t1
set c1=c1 +(select max(a.c2)
from v1 a
where a.c1 = t1.c1) ;
affected rows: 8
info: Rows matched: 8  Changed: 8  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1;
concat(old_c1,'->',c1)	c3	Changed
1->3	1	*
1->3	2	*
1->3	3	*
2->4	4	*
2->4	5	*
2->4	6	*
2->4	7	*
2->4	8	*
rollback;
#
# Update throw a view
#
start transaction;
update v1
set c1=c1 + (select max(a.c2)
from t1 a
where a.c1 = v1.c1) +10
where c3 > 3;
affected rows: 1
info: Rows matched: 1  Changed: 1  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1;
concat(old_c1,'->',c1)	c3	Changed
NULL	1	 
NULL	2	 
NULL	3	 
NULL	4	 
2->17	5	*
NULL	6	 
NULL	7	 
NULL	8	 
rollback;
#
# Update through a view and using the view in subquery
#
start transaction;
update v1
set c1=c1 + 1
where c1 <2
and exists (select 'X'
                 from v1 a
where a.c1 = v1.c1);
affected rows: 1
info: Rows matched: 1  Changed: 1  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1;
concat(old_c1,'->',c1)	c3	Changed
NULL	1	 
1->2	2	*
NULL	3	 
NULL	4	 
NULL	5	 
NULL	6	 
NULL	7	 
NULL	8	 
rollback;
#
# Update through  a view and using the view in subquery
#
start transaction;
update v1
set c1=(select max(a.c1)+10
from v1 a
where a.c1 = v1.c1)
where c1 <10
and exists (select 'X'
                 from v1 a
where a.c2 = v1.c2);
affected rows: 2
info: Rows matched: 2  Changed: 2  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1;
concat(old_c1,'->',c1)	c3	Changed
NULL	1	 
1->11	2	*
NULL	3	 
NULL	4	 
2->12	5	*
NULL	6	 
NULL	7	 
NULL	8	 
rollback;
#
# Update of the index or primary key (c3)
#
start transaction;
explain update t1 set c3=c3+10 where c2 in (select distinct a.c2 from t1 a where t1.c1=a.c1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1	ALL	t1_c2	NULL	NULL	NULL	8	Using where
1	PRIMARY	a	ref	t1_c2	t1_c2	10	test.t1.c2,test.t1.c1	1	Using index; FirstMatch(t1)
update t1 set c3=c3+10 where c2 in (select distinct a.c2 from t1 a where t1.c1=a.c1);
affected rows: 8
info: Rows matched: 8  Changed: 8  Warnings: 0
select c3 from t1;
c3
11
12
13
14
15
16
17
18
rollback;
#
# update with a limit
#
start transaction;
update t1
set c1=(select a.c3
from t1 a
where a.c3 = t1.c3)
limit 2;
affected rows: 2
info: Rows matched: 2  Changed: 2  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1 ;
concat(old_c1,'->',c1)	c3	Changed
1->1	1	 
1->2	2	*
NULL	3	 
NULL	4	 
NULL	5	 
NULL	6	 
NULL	7	 
NULL	8	 
rollback;
#
# update with a limit and an order by
#
start transaction;
update t1
set c1=(select a.c3
from t1 a
where a.c3 = t1.c3)
order by c3 desc limit 2;
affected rows: 2
info: Rows matched: 2  Changed: 2  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1 ;
concat(old_c1,'->',c1)	c3	Changed
NULL	1	 
NULL	2	 
NULL	3	 
NULL	4	 
NULL	5	 
NULL	6	 
2->7	7	*
2->8	8	*
rollback;
Test with a primary key on updated columns
drop index t1_c3 on t1;
alter table t1 add primary key (c3);
#
# Update a with value from subquery on the same table, no search clause. ALL access
#
start transaction;
update t1
set c1=(select a.c3
from t1 a
where a.c3 = t1.c3);
affected rows: 8
info: Rows matched: 8  Changed: 8  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1 ;
concat(old_c1,'->',c1)	c3	Changed
1->1	1	 
1->2	2	*
1->3	3	*
2->4	4	*
2->5	5	*
2->6	6	*
2->7	7	*
2->8	8	*
rollback;
#
# Update with search clause on the same table
#
start transaction;
update t1
set c1=10
where c1 <2
and exists (select 'X'
                 from t1 a
where a.c1 = t1.c1);
affected rows: 3
info: Rows matched: 3  Changed: 3  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1 ;
concat(old_c1,'->',c1)	c3	Changed
1->10	1	*
1->10	2	*
1->10	3	*
NULL	4	 
NULL	5	 
NULL	6	 
NULL	7	 
NULL	8	 
rollback;
#
# Update via RANGE or INDEX access if an index or a primary key exists
#
explain update t1 set c1=0 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 > 3;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1	range	t1_c2	t1_c2	5	NULL	2	Using where
2	DEPENDENT SUBQUERY	a	ref	t1_c2	t1_c2	5	test.t1.c2	1	Using index
start transaction;
update t1 set c1=c1+10 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 >= 3;
affected rows: 4
info: Rows matched: 4  Changed: 4  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1;
concat(old_c1,'->',c1)	c3	Changed
NULL	1	 
NULL	2	 
1->11	3	*
NULL	4	 
NULL	5	 
2->12	6	*
2->12	7	*
2->12	8	*
rollback;
#
# Update with order by
#
start transaction;
update t1 set c1=c1+10 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 >= 3 order by c2;
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1;
concat(old_c1,'->',c1)	c3	Changed
NULL	1	 
NULL	2	 
1->11	3	*
NULL	4	 
NULL	5	 
2->12	6	*
2->12	7	*
2->12	8	*
rollback;
#
Update using a view in subquery
#
start transaction;
update t1
set c1=c1 +(select max(a.c2)
from v1 a
where a.c1 = t1.c1) ;
affected rows: 8
info: Rows matched: 8  Changed: 8  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1;
concat(old_c1,'->',c1)	c3	Changed
1->3	1	*
1->3	2	*
1->3	3	*
2->4	4	*
2->4	5	*
2->4	6	*
2->4	7	*
2->4	8	*
rollback;
#
# Update throw a view
#
start transaction;
update v1
set c1=c1 + (select max(a.c2)
from t1 a
where a.c1 = v1.c1) +10
where c3 > 3;
affected rows: 1
info: Rows matched: 1  Changed: 1  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1;
concat(old_c1,'->',c1)	c3	Changed
NULL	1	 
NULL	2	 
NULL	3	 
NULL	4	 
2->17	5	*
NULL	6	 
NULL	7	 
NULL	8	 
rollback;
#
# Update through a view and using the view in subquery
#
start transaction;
update v1
set c1=c1 + 1
where c1 <2
and exists (select 'X'
                 from v1 a
where a.c1 = v1.c1);
affected rows: 1
info: Rows matched: 1  Changed: 1  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1;
concat(old_c1,'->',c1)	c3	Changed
NULL	1	 
1->2	2	*
NULL	3	 
NULL	4	 
NULL	5	 
NULL	6	 
NULL	7	 
NULL	8	 
rollback;
#
# Update through  a view and using the view in subquery
#
start transaction;
update v1
set c1=(select max(a.c1)+10
from v1 a
where a.c1 = v1.c1)
where c1 <10
and exists (select 'X'
                 from v1 a
where a.c2 = v1.c2);
affected rows: 2
info: Rows matched: 2  Changed: 2  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1;
concat(old_c1,'->',c1)	c3	Changed
NULL	1	 
1->11	2	*
NULL	3	 
NULL	4	 
2->12	5	*
NULL	6	 
NULL	7	 
NULL	8	 
rollback;
#
# Update of the index or primary key (c3)
#
start transaction;
explain update t1 set c3=c3+10 where c2 in (select distinct a.c2 from t1 a where t1.c1=a.c1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1	ALL	t1_c2	NULL	NULL	NULL	8	Using where
1	PRIMARY	a	ref	t1_c2	t1_c2	10	test.t1.c2,test.t1.c1	1	Using index; FirstMatch(t1)
update t1 set c3=c3+10 where c2 in (select distinct a.c2 from t1 a where t1.c1=a.c1);
affected rows: 8
info: Rows matched: 8  Changed: 8  Warnings: 0
select c3 from t1;
c3
11
14
12
15
13
16
17
18
rollback;
#
# update with a limit
#
start transaction;
update t1
set c1=(select a.c3
from t1 a
where a.c3 = t1.c3)
limit 2;
affected rows: 2
info: Rows matched: 2  Changed: 2  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1 ;
concat(old_c1,'->',c1)	c3	Changed
1->1	1	 
1->2	2	*
NULL	3	 
NULL	4	 
NULL	5	 
NULL	6	 
NULL	7	 
NULL	8	 
rollback;
#
# update with a limit and an order by
#
start transaction;
update t1
set c1=(select a.c3
from t1 a
where a.c3 = t1.c3)
order by c3 desc limit 2;
affected rows: 2
info: Rows matched: 2  Changed: 2  Warnings: 0
select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1 ;
concat(old_c1,'->',c1)	c3	Changed
NULL	1	 
NULL	2	 
NULL	3	 
NULL	4	 
NULL	5	 
NULL	6	 
2->7	7	*
2->8	8	*
rollback;
# Update with error "Subquery returns more than 1 row"
update t1 set c2=(select c2 from t1);
ERROR 21000: Subquery returns more than 1 row
# Update with error "Subquery returns more than 1 row" and order by
update t1 set c2=(select c2 from t1) order by c3;
ERROR 21000: Subquery returns more than 1 row
Duplicate value on update a primary key
start transaction;
update t1 set c3=0 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 >= 3;
ERROR 23000: Duplicate entry '0' for key 'PRIMARY'
rollback;
Duplicate value on update a primary key with ignore
start transaction;
update ignore t1 set c3=0 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 >= 3;
affected rows: 4
info: Rows matched: 4  Changed: 4  Warnings: 0
rollback;
Duplicate value on update a primary key and limit
start transaction;
update t1 set c3=0 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 >= 3 limit 2;
ERROR 23000: Duplicate entry '0' for key 'PRIMARY'
rollback;
Duplicate value on update a primary key with ignore and limit
start transaction;
update ignore t1 set c3=0 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 >= 3 limit 2;
affected rows: 2
info: Rows matched: 2  Changed: 2  Warnings: 0
rollback;
# Update no rows found
update t1
set c1=10
where c1 <2
and exists (select 'X'
                 from t1 a
where a.c1 = t1.c1 + 10);
affected rows: 0
info: Rows matched: 0  Changed: 0  Warnings: 0
# Update no rows changed
drop trigger trg_t1;
start transaction;
update t1
set c1=c1
where c1 <2
and exists (select 'X'
                 from t1 a
where a.c1 = t1.c1);
affected rows: 0
info: Rows matched: 3  Changed: 0  Warnings: 0
rollback;
#
# Check call of after trigger
#
create or replace trigger trg_t2 after update on t1 for each row
begin
declare msg varchar(100);
if (new.c3 = 5) then
set msg=concat('in after update trigger on ',new.c3);
SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = msg;
end if;
end;
/
update t1 set c1=2 where c3 in (select distinct a.c3 from t1 a where a.c1=t1.c1);
ERROR 45000: in after update trigger on 5
#
# Check update with order by and after trigger
#
update t1 set c1=2 where c3 in (select distinct a.c3 from t1 a where a.c1=t1.c1) order by t1.c2;
ERROR 45000: in after update trigger on 5
drop view v1;
#
# Check update on view with check option
#
create view v1 as select * from t1 where c2=2 with check option;
start transaction;
update v1 set c2=3 where c1=1;
ERROR 44000: CHECK OPTION failed `test`.`v1`
rollback;
start transaction;
update v1 set c2=(select max(c3) from v1) where c1=1;
ERROR 44000: CHECK OPTION failed `test`.`v1`
rollback;
start transaction;
update v1 set c2=(select min(va.c3) from v1 va), c1=0 where c1=1;
rollback;
drop view v1;
drop table t1;
#
# Test with a temporary table
#
create temporary table t1 (c1 integer, c2 integer, c3 integer) engine=InnoDb;
insert into t1(c1,c2,c3) values (1,1,1);
insert into t1(c1,c2,c3) values (1,2,2);
insert into t1(c1,c2,c3) values (1,3,3);
insert into t1(c1,c2,c3) values (2,1,4);
insert into t1(c1,c2,c3) values (2,2,5);
insert into t1(c1,c2,c3) values (2,3,6);
insert into t1(c1,c2,c3) values (2,4,7);
insert into t1(c1,c2,c3) values (2,5,8);
start transaction;
update t1
set c1=(select a.c2
from t1 a
where a.c3 = t1.c3) limit 3;
affected rows: 2
info: Rows matched: 3  Changed: 2  Warnings: 0
select * from t1 ;
c1	c2	c3
1	1	1
2	2	2
3	3	3
2	1	4
2	2	5
2	3	6
2	4	7
2	5	8
rollback;
drop table t1;
#
# Test on dynamic columns (blob)
#
create table assets (
item_name varchar(32) primary key, -- A common attribute for all items
dynamic_cols  blob  -- Dynamic columns will be stored here
);
INSERT INTO assets VALUES ('MariaDB T-shirt', COLUMN_CREATE('color', 'blue', 'size', 'XL'));
INSERT INTO assets VALUES ('Thinkpad Laptop', COLUMN_CREATE('color', 'black', 'price', 500));
SELECT item_name, COLUMN_GET(dynamic_cols, 'color' as char) AS color FROM assets;
item_name	color
MariaDB T-shirt	blue
Thinkpad Laptop	black
UPDATE assets SET dynamic_cols=COLUMN_ADD(dynamic_cols, 'warranty', '3 years') WHERE item_name='Thinkpad Laptop';
SELECT item_name, COLUMN_GET(dynamic_cols, 'warranty' as char) AS color FROM assets;
item_name	color
MariaDB T-shirt	NULL
Thinkpad Laptop	3 years
UPDATE assets SET dynamic_cols=COLUMN_ADD(dynamic_cols, 'warranty', '4 years')
WHERE item_name in (select b.item_name
from assets b
where COLUMN_GET(b.dynamic_cols, 'color' as char) ='black');
SELECT item_name, COLUMN_GET(dynamic_cols, 'warranty' as char) AS color FROM assets;
item_name	color
MariaDB T-shirt	NULL
Thinkpad Laptop	4 years
UPDATE assets SET dynamic_cols=COLUMN_ADD(dynamic_cols, 'warranty', (select COLUMN_GET(b.dynamic_cols, 'color' as char)
from assets b
where assets.item_name = item_name));
SELECT item_name, COLUMN_GET(dynamic_cols, 'warranty' as char) AS color FROM assets;
item_name	color
MariaDB T-shirt	blue
Thinkpad Laptop	black
drop table assets ;
#
# Test on fulltext columns
#
CREATE TABLE ft2(copy TEXT,FULLTEXT(copy)) ENGINE=MyISAM;
INSERT INTO ft2(copy) VALUES
('MySQL vs MariaDB database'),
('Oracle vs MariaDB database'),
('PostgreSQL vs MariaDB database'),
('MariaDB overview'),
('Foreign keys'),
('Primary keys'),
('Indexes'),
('Transactions'),
('Triggers');
SELECT * FROM ft2 WHERE MATCH(copy) AGAINST('database');
copy
MySQL vs MariaDB database
Oracle vs MariaDB database
PostgreSQL vs MariaDB database
update ft2 set copy = (select max(concat('mykeyword ',substr(b.copy,1,5))) from ft2 b WHERE MATCH(b.copy) AGAINST('database'))
where MATCH(copy) AGAINST('keys');
SELECT * FROM ft2 WHERE MATCH(copy) AGAINST('mykeyword');
copy
mykeyword Postg
mykeyword Postg
drop table ft2;
#
# Test with MyISAM
#
create table t1 (old_c1 integer, old_c2 integer,c1 integer, c2 integer, c3 integer) engine=MyISAM;
insert t1 (c1,c2,c3) select 0,seq,seq%10 from seq_1_to_500;
insert t1 (c1,c2,c3) select 1,seq,seq%10 from seq_1_to_400;
insert t1 (c1,c2,c3) select 2,seq,seq%10 from seq_1_to_300;
insert t1 (c1,c2,c3) select 3,seq,seq%10 from seq_1_to_200;
create index t1_idx1 on t1(c3);
analyze table t1;
Table	Op	Msg_type	Msg_text
test.t1	analyze	status	Table is already up to date
update t1 set c1=2 where exists (select 'x' from t1);
select count(*) from t1 where c1=2;
count(*)
1400
update t1 set c1=3 where c3 in (select c3 from t1 b where t1.c3=b.c1);
select count(*) from t1 where c1=3;
count(*)
140
drop table t1;
#
# Test error on multi_update conversion on view with order by or limit
#
create table t1 (c1 integer) engine=InnoDb;
create table t2 (c1 integer) engine=InnoDb;
create view v1 as select t1.c1 as "t1c1" ,t2.c1 as "t2c1" from t1,t2 where t1.c1=t2.c1;
update v1 set t1c1=2 order by 1;
ERROR 42S22: Unknown column '1' in 'order clause'
update v1 set t1c1=2 limit 1;
drop table t1;
drop table t2;
drop view v1;