摘要：
declare @t1 table ( id int , val varchar(20)) insert into @t1 select 1 , 'a' union select 2 , 'b' union select 3 , 'd' ;declare @t2 table ( id int , val varchar(20)) insert into @t2 select 2 , 'b' union select 3 , 'b' union select 4 , 'c' ;select * fro 阅读全文