sql server join ,inner join ,left join ,right join 的使用

测试数据脚本

CREATE TABLE Atable
  ( 
     S#    INT, 
     Sname nvarchar(32), 
     Sage  INT, 
     Sfrom  nvarchar(8) 
  ) 


 insert into Atable 
 select 1,N'李四',18,N'A' union all
 select 2,N'tom',19, N'A' union all
 select 3,N'刘一',17,N'A' union all
 select 4,N'jack',18,N'A'

 

 CREATE TABLE Btable
  ( 
     S#    INT, 
     Sname nvarchar(32), 
     Sage  INT, 
     Sfrom  nvarchar(8) 
  ) 


 insert into Btable
 select 1,N'刘一',18,N'B' union all
 select 2,N'钱二',19,N'B' union all
 select 3,N'张三',17,N'B' union all
 select 4,N'李四',18,N'B'