MySQL 集合 补集

http://topic.csdn.net/t/20030918/10/2272819.html

 

SELECT   
       t1.ID,   t1.Content   
FROM   
             表1   as   t1  
 LEFT   JOIN   
             表2   as   t2   
ON   

           t2.ID=t1.ID   

WHERE   

           t2.ID   is   NULL