oracle 的交并差函数，intersect;union;minus。

--创建TABLE_A
create table TABLE_A  
(  
 A varchar2(10),  
 B varchar2(10)  
);
--给TABLE_A添加数据
insert into TABLE_A  values(‘a1‘,‘b1‘);  
insert into TABLE_A  values(‘a2‘,‘b2‘);  
insert into TABLE_A  values(‘a3‘,‘b3‘);  


--创建TABLE_B 
create table TABLE_B  
(  
 A varchar2(10),  
 B varchar2(10)  
);
--给TABLE_B添加数据
insert into TABLE_B  values(‘a1‘,‘b1‘);  
insert into TABLE_B  values(‘a2‘,‘b2‘);  
insert into TABLE_B  values(‘a4‘,‘b4‘);  
 

SELECT A,B FROM TABLE_A 
INTERSECT     
SELECT A,B FROM TABLE_B;

--结果
A         B
------------
a1        b1
a2        b2

--  TABLE_A和TABLE_B会去除重复数据
SELECT A,B FROM TABLE_A
UNION  
SELECT A,B FROM TABLE_B;  

--结果
A         B
------------
a1        b1
a2        b2
a3        b3
a4        b4

--  TABLE_A和TABLE_B中的所有数据
SELECT A,B FROM TABLE_A 
UNION ALL   
SELECT A,B FROM TABLE_B; 

--结果
A         B
------------
a1        b1
a1        b1
a2        b2
a2        b2
a3        b3
a4        b4

SELECT A,B FROM TABLE_A
MINUS  
SELECT A,B FROM TABLE_B;

--结果
A        B
-----------
a3       b3