数据库中多表的连接

数据库中多表的连接

1.外连接

select   *   from  T_N  left  join  T_S  on   T_N.id=T_S.id 

 

select   *   from  T_N  right  join  T_S  on   T_N.id=T_S.id 

select * from T_N full join T_S on T_N.id=T_S.id 

2.内连接

select   *   from   T_N   join   T_S   on   T_N.id=T_S.id 

3.交叉连接

select   *   from   T_N  cross  join   T_S  

最后的总结

//建立的有外连接的充值总和、消费总和的视图

SELECT Recharge_Info.CardID, Line_info.cardID AS LcardID, SUM(Recharge_Info.AddMoney) AS sumAddMoney, SUM(Line_info.consume) AS sumConsume
FROM  Line_info RIGHT OUTER JOIN  Recharge_Info ON Line_info.cardID = Recharge_Info.CardID
GROUP BY Recharge_Info.CardID, Line_info.cardID