WITH cte AS (
SELECT roleid,permissionid,
row_number() OVER(PARTITION BY roleid,permissionid
ORDER BY roleid,permissionid) AS [rn]
FROM rolepermissionrecords
)
DELETE cte WHERE [rn] > 1
T-SQL 删除重复数据SQL,布布扣,bubuko.com
原文：http://www.cnblogs.com/Flyear/p/3586157.html