Sql server 2008 组中具有最大值的特定行
我有以下SQL SERVER表:Sql server 2008 组中具有最大值的特定行,sql-server-2008,tsql,max,Sql Server 2008,Tsql,Max,我有以下SQL SERVER表: +--------+-------+-------+------+ | Person | Phone | Count | Rank | +--------+-------+-------+------+ | A | X | 1 | 1 | | B | X | 9 | 2 | | C | X | 5 | 3 | | T | Y | 6 | 1
+--------+-------+-------+------+
| Person | Phone | Count | Rank |
+--------+-------+-------+------+
| A | X | 1 | 1 |
| B | X | 9 | 2 |
| C | X | 5 | 3 |
| T | Y | 6 | 1 |
| S | Y | 2 | 2 |
+--------+-------+-------+------+
我需要结果为个人和电话值,其中排名等于1,但为特定电话的最大计数值,例如:
+--------+-------+----------+------+
| Person | Phone | MaxCount | Rank |
+--------+-------+----------+------+
| A | X | 9 | 1 |
| T | Y | 6 | 1 |
+--------+-------+----------+------+
我可以在表上加入两次,但我想知道是否可以使用MAX来实现这一点?您可以使用MAX(Count)OVER(电话分区)
,例如使用CTE:
WITH CTE AS
(
SELECT Person,
Phone,
MaxCount = MAX(Count)OVER(PARTITION BY Phone),
Rank
FROM dbo.TableName
)
SELECT Person,
Phone,
MaxCount,
Rank
FROM CTE
WHERE Rank = 1
您可以使用子查询:
SELECT T.Person, T.Phone, (SELECT MAX(Count)
FROM YourTable AS TI
WHERE TI.Phone = T.Phone) AS MaxCount, T.[Rank]
FROM YourTable AS T
WHERE T.[RANK] = 1
另一种解决方案是使用
外部应用
如下:
SELECT Person,
Phone,
MaxCount,
[Rank]
FROM YourTable t1
OUTER APPLY (SELECT MAX([count]) AS MaxCount FROM YourTable WHERE Phone = t1.Phone) oa
WHERE [Rank] = 1
您知道您也可以使用
ROW\u NUMBER()OVER(按电话顺序按ID划分)
来获得排名
“列”?不知道为什么会被否决。。。有什么想法吗?我没有投反对票,我也不知道为什么。