将多行中的数据合并为一行

Question

我在SQL中合并（合并）行时遇到困难：我正在寻找包含

的行

CLIENTID，所有级别的总计数，级别计数（每个级别）。

以下是一个例子：

ClientID    Total Counts    Level1  Level2  Level3
1234566     12              9        3      0

这是我的代码，我已经扭曲并转向了它但它总是很短：除了一个之外，它在每个级别都给我空值。但我希望数据全部合并为一行。非常感谢您提前

            SELECT u.clientID AS CLIENTID_SHORT, 
            CASE WHEN LEVEL='1' THEN COUNT(*) END AS Level1,
            CASE WHEN LEVEL='2' THEN COUNT(*) END AS Level2,
            CASE WHEN LEVEL='3' THEN COUNT(*) END AS Level3,
            CASE WHEN LEVEL='4' THEN COUNT(*) END AS Level4,
            CASE WHEN LEVEL='5' THEN COUNT(*) END AS Level5
            FROM CLIENTPROFILE u
            GROUP BY u.ClientID, u.LEVEL
            ORDER BY CLIENTID_SHORT

Answer 1

在count声明

之上应用case

SELECT u.clientID AS CLIENTID_SHORT,
       Count(*) AS TotalLevelCount,
       Count(CASE WHEN LEVEL = 1 THEN 1 END) AS Level1,
       Count(CASE WHEN LEVEL = 2 THEN 1 END) AS Level2,
       Count(CASE WHEN LEVEL = 3 THEN 1 END) AS Level3,
       Count(CASE WHEN LEVEL = 4 THEN 1 END) AS Level4,
       Count(CASE WHEN LEVEL = 5 THEN 1 END) AS Level5
FROM   CLIENTPROFILE u
WHERE  LEVEL >= 1
       AND Level <= 5
GROUP  BY u.ClientID
ORDER  BY CLIENTID_SHORT 

注意：在检查整数列时，您不必使用单引号。