【學習筆記】SqlServer刪除重複數據保留一條（好用）

1、查詢出重複的數據，Id只保留其中一個

SELECT MIN(Id) Id,Name FROM dbo.City 
GROUP BY Name
HAVING COUNT(1) >  1

2、然後使用刪除時Join上面的表

DELETE C FROM City C 
JOIN (
    SELECT MIN(Id) Id,Name FROM dbo.City
    GROUP BY Name
    HAVING COUNT(1) >  1
) TMP ON C.Name = TMP.Name AND C.Id <> TMP.Id