思路:1.找出某个字段相同的数据,给他们分组,筛选出Id
2.找出相同数据中的最小的数据保留
3.删除 满足相同字段数据,但是数据又不是最小的数据。
- DELETE FROM dbo.TableSign
- WHERE SelfID IN
- (SELECT SelfID FROM dbo.Table T
- WHERE EXISTS (SELECT 字段1, 字段2, 字段3 FROM dbo.TableSign WHERE 字段1= T.字段1 AND 字段2= T.字段2
- AND 字段3 = T.字段3 GROUP BY 字段1, 字段2, 字段3 HAVING COUNT(*) > 1)
- AND T.SelfID NOT IN (SELECT MIN(SelfID) FROM dbo.Table GROUP BY 字段1, 字段2, 字段3 HAVING COUNT(*) > 1))