mysql 或者sqlserver 我用的这两种sql差异大么? 我要是学习数据库模型的话学什么比较通用呢?
在SQL SERVER中,你还是分开写吧: delete from randchoice where randchoice.id=(select id from userinfo where username='$username') go delete from answer where answer.id=(select id from userinfo where username='$username') go delete from defen where defen.id=(select id from userinfo where username='$username') go
我用的这两种sql差异大么?
我要是学习数据库模型的话学什么比较通用呢?
delete from randchoice where randchoice.id=(select id from userinfo where username='$username')
go
delete from answer where answer.id=(select id from userinfo where username='$username')
go
delete from defen where defen.id=(select id from userinfo where username='$username')
go