create trigger TRI_TEST before insert on A for each row begin if (select count(*) from A)>=10000 then delete from A where ID=(select min(ID) from A) end if end
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'end if
delimiter $$ create trigger TRI_TEST before insert on A for each row begin if (select count(*) from A)>=10000 then delete from A where ID=(select min(ID) from A); end if; end$$ delimiter ; 自己试试
before insert on A
for each row
begin
if (select count(*) from A)>=10000 then
delete from A where ID=(select min(ID) from A)
end if
end
create trigger TRI_TEST
before insert on A
for each row
begin
if (select count(*) from A)>=10000 then
delete from A where ID=(select min(ID) from A);
end if;
end$$
delimiter ;
自己试试
大哥,我按照这个做法触发器建立成功,可是当插入数据的时候会不给插入数据。然后我在网上看了很多好像跟你第一次说的一样,Mysql不允许A表触发器操作A表??