Sql去重复之------Group by语句***打乱结果集排序顺序的解决方法***(用ROW_NUMBER() OVER(PARTITION BY City ORDER BY id asc)去重复，兼排序)

1，例如我用下边语句SELECT City FROM dbo.LISTAreas AS la WHERE Pro LIKE '%河南%'查询，返回下边结果集。(注意，select查询默认是按id升序排序的)

2，下边语句中，加上group by去重复以后，就会打乱结果集的顺序(郑州市，跑到了最后边)：

SELECT City FROM dbo.LISTAreas AS la WHERE Pro LIKE '%河南%' GROUP BY City

3，解决方法，用row_number()去重复，然后再用order by id asc排序

SELECT  city
FROM    ( SELECT    ROW_NUMBER() OVER ( PARTITION BY City ORDER BY id ASC ) AS allcount ,
                    id ,
                    city
          FROM      dbo.LISTAreas AS la
          WHERE     Pro LIKE '%河南%'
        ) AS temp
WHERE   allcount = 1
ORDER BY id ASC

---查询结果如下：