一、if( OBJECT_ID('dbo.student') is not null and OBJECTPROPERTY(OBJECT_ID('dbo.student'),N'IsUserTable') = 1 )
drop table student
二、if exists (select * from sysobjects where id = object_id(N'[dbo].[student]') and OBJECTPROPERTY(id,N'IsUserTable') = 1)
drop Table [dbo].[student]
三、if( OBJECT_ID('dbo.orders') is not null )
drop table [dbo].[orders]
一二种都可以,倾向于第一种,但是本人分不出优劣,第三种写法需要确保表为非系统表 , 不然 就杯具鸟。