2011-10-01 72 views
1

例如说我有如下表(正式成员之间的连接)在SQL结合共同的价值观

connectionA ConnectionB 
    887    225 
    129    887 
    225    887 
    887    562 
    562    887 

我怎么能够使用SQL来找到所有地方都A连接到B行反之亦然。查询将返回(不允许重复):

connectionA ConnectionB 
    887    225 
    887    562 

回答

3
SELECT T1.connectionA, T1.connectionB 
FROM yourtable T1 
JOIN yourtable T2 
ON T1.connectionA = T2.connectionB 
AND T2.connectionA = T1.connectionB 
WHERE T1.connectionA > T1.connectionB