# Include to test update with same table as source and target --echo # --echo # Update a with value from subquery on the same table, no search clause. ALL access --echo # #Enable view protocol after fix MDEV-29207 --disable_view_protocol start transaction; --enable_info ONCE update t1 set c1=(select a.c3 from t1 a where a.c3 = t1.c3); select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1 ; rollback; --echo # --echo # Update with search clause on the same table --echo # start transaction; --enable_info ONCE update t1 set c1=10 where c1 <2 and exists (select 'X' from t1 a where a.c1 = t1.c1); select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1 ; rollback; --echo # --echo # Update via RANGE or INDEX access if an index or a primary key exists --echo # explain update t1 set c1=0 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 > 3; start transaction; --enable_info ONCE update t1 set c1=c1+10 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 >= 3; select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1; rollback; --echo # --echo # Update with order by --echo # 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; rollback; --echo # --echo Update using a view in subquery --echo # start transaction; --enable_info ONCE update t1 set c1=c1 +(select max(a.c2) from v1 a where a.c1 = t1.c1) ; select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1; rollback; --echo # --echo # Update throw a view --echo # start transaction; --enable_info ONCE update v1 set c1=c1 + (select max(a.c2) from t1 a where a.c1 = v1.c1) +10 where c3 > 3; select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1; rollback; --echo # --echo # Update through a view and using the view in subquery --echo # start transaction; --enable_info ONCE update v1 set c1=c1 + 1 where c1 <2 and exists (select 'X' from v1 a where a.c1 = v1.c1); select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1; rollback; --echo # --echo # Update through a view and using the view in subquery --echo # start transaction; --enable_info ONCE 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); select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1; rollback; --echo # --echo # Update of the index or primary key (c3) --echo # start transaction; explain update t1 set c3=c3+10 where c2 in (select distinct a.c2 from t1 a where t1.c1=a.c1); --enable_info ONCE update t1 set c3=c3+10 where c2 in (select distinct a.c2 from t1 a where t1.c1=a.c1); select c3 from t1; rollback; --echo # --echo # update with a limit --echo # start transaction; --enable_info ONCE update t1 set c1=(select a.c3 from t1 a where a.c3 = t1.c3) limit 2; select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1 ; rollback; --echo # --echo # update with a limit and an order by --echo # start transaction; --enable_info ONCE update t1 set c1=(select a.c3 from t1 a where a.c3 = t1.c3) order by c3 desc limit 2; select concat(old_c1,'->',c1),c3, case when c1 != old_c1 then '*' else ' ' end "Changed" from t1 ; rollback; --enable_view_protocol