mysql触发器写法?
已知表A，要实现如下功能：当表A的记录超过1W条时，则删除第一条记录；即保证数据库中表A只有1W条最新记录。
用触发器实现，代码如何写？请教了！
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 $$
create trigger TRI_TEST
before insert on A
for each row
begin
if (select count(*) from A)>=10000 then
delete from A where ID=(select min(ID) from A);
end if;
end$$
delimiter ;
自己试试
