1.隐式内连接
select * from A,B where
A.id=B.id
2.显示内连接
select * from A inner join B on
A.id=B.id
3.左外连
select * from A left join B on
A.id=B.id
4.右外连
select * from A right join B on
A.id=B.id
4.左独有
select * from A left join B on
A.id=B.id
where
B.id
is null
5.右独有
select * from A right join B on
A.id=B.id
where
A.id
is null
6.求差集
select * from A left join B on
A.id=B.id
where
B.id
is null
union
select * from A right join B on
A.id=B.id
where
A.id
is null
7.全连
select * from A left join B on
A.id=B.id
union
select * from A right join B on
A.id=B.id
8.笛卡尔积
select * from A cross join B
cross join：交叉连接，得到的结果是两个表的乘积，即笛卡尔积
示例：
