呵呵,纠正: DELIMITER $$DROP TRIGGER /*!50032 IF EXISTS */ `zz`.`gg`$$CREATE /*!50017 DEFINER = 'root'@'localhost' */ TRIGGER `zz`.`gg` AFTER INSERT ON `zz`.`bbb` FOR EACH ROW BEGIN if (select count(*) from bbb)>9 then delete from bbb where cid=new.cid; end if; END; $$DELIMITER ;
插入之前要判断是否>50,是则提示退出
DELIMITER $$DROP TRIGGER /*!50032 IF EXISTS */ `zz`.`gg`$$CREATE
/*!50017 DEFINER = 'root'@'localhost' */
TRIGGER `zz`.`gg` AFTER INSERT ON `zz`.`bbb`
FOR EACH ROW BEGIN
if (select count(*) from bbb)>9 then
delete from bbb where cid=new.cid;
end if;
END;
$$DELIMITER ;
将9改为你的设定数