联结查询条件的多样化使用!
不知道各位同仁在涉及到查询的时候有没有遇到下列语句:
表A,B
select * from A join B on A.id=B.id where A.amount>0
select * from A join B on A.id=B.id and A.amount>0
select * from A left join B on A.id=B.id where A.amount>0
select * from A lef join B on A.id=B.id and A.amount>0
select * from A right join B on A.id=B.id where A.amount>0
select * from A right join B on A.id=B.id and A.amount>0
select * from A full outer join B on A.id=B.id where A.amount>0
select * from A full outer join B on A.id=B.id and A.amount>0
各位可以谈谈自己在用到这些SQL语句的问题