按照自己的理解做个笔记，以下在Sql Server2005和Oracle92中都运行通过：

create table a(

   aid varchar(2),   aname varchar(10),   bid varchar(2) );

create table b(

   bid varchar(2),   bname varchar(10));

insert into a values('s1','sname1','c1');insert into a values('s2','sname2','c2');insert into a values('s3','sname3','c3');insert into a values('s4','sname4','c4');insert into a values('s5','sname5','c5');

insert into b values('c1','cname1');

insert into b values('c2','cname2');insert into b values('c3','cname3');insert into b values('c6','cname6');insert into b values('c7','cname7');

--Iner Join和Join和, (如select * from a,b where a.id=b.id)，这三个效果一样.

select * from  a ,  b where  a.bid = b.bid;

select * from a join b on a.bid = b.bid;select * from a inner join b on a.bid = b.bid;

 

 

 

--Left Join和Left Outer Join 左连接、左外连接，效果一样。

select * from a left join b on a.bid = b.bid;select * from a left outer join b on a.bid = b.bid;

 

 

 

 

 

--Right Join和Right Outer Join 右连接、右外连接，效果一样。

select * from a right join b on a.bid = b.bid;

select * from a right outer join b on a.bid = b.bid;

 

 

 

 

 

 

--Full Join和Full Outer Join 全连接、全外连接，效果一样。

select * from a full join b on a.bid = b.bid;

select * from  a full outer join  b on a.bid = b.bid;

 

 

 

 

--Cross Join，不带where，即笛卡尔积。

select * from a  Cross join b;

 

 

 

 

总结：只有以上的的连接词，像什么Left Inner Join、Right Full Join之类的组合都没有，想都别想！！