Question

我有3张桌子互相联系，以获取我的客户的信息。我的一些客户是多种族的，这使得表有重复的行。我想知道我是否可以识别一个新值，并说一个ID是否重复，在比赛中给了我Multiracial作为值？
我有这个：

ID     Name     Age   Race
4000    Duc      25    Philipino
4000    Duc      25    Chinese
4001    Daniel   36    African American
4002    Nicole   20    White
4002    Nicole   20    Middle East

我想要这个

ID      Name      Age    Race
4000    Duc       25     Multiracial
4001    Daniel    36     African American
4002    Nicole    20     Multiracial

我非常感谢任何帮助

Answer 1

你可以这样做（应该适用于MS SQL和MySQL）：

SELECT ID,Name,Age, CASE WHEN COUNT(Race)>1 THEN 'Mulitiracial' ELSE MAX(Race) END Race
FROM Src
GROUP BY ID,Name,Age

要测试您的数据（仅在MS SQL中使用CTE），我使用了以下内容：

WITH Src AS
(
    SELECT * FROM (VALUES
    (4000, 'Duc   ', 25, 'Philipino'        ),
    (4000, 'Duc   ', 25, 'Chinese'          ),
    (4001, 'Daniel', 36, 'African American' ),
    (4002, 'Nicole', 20, 'White           ' ),
    (4002, 'Nicole', 20, 'Middle East     ' )
    )T (ID,Name,Age,Race)
)
SELECT ID,Name,Age, CASE WHEN COUNT(Race)>1 THEN 'Mulitiracial' ELSE MAX(Race) END Race
FROM Src
GROUP BY ID,Name,Age

Answer 2

;WITH CTE
AS
(SELECT ID,NAME,AGE,RACE,COUNT(*) OVER (PARTITION BY ID,NAME,AGE ORDER BY (SELECT NULL)) AS CNT
FROM
#TEMP
)
SELECT ID,NAME,AGE,CASE WHEN CNT>1 THEN 'MULTIRACILA' ELSE RACE END
FROM CTE
GROUP BY 
ID,NAME,AGE,CASE WHEN CNT>1 THEN 'MULTIRACILA' ELSE RACE END

如何识别新值

2 个答案: