GROUP BY 不适用于多个 Case 语句和左连接

Question

我有两个表，我正在尝试编写一个包含多个 CASE 语句的 GROUP BY 子句，以便将数据分组为每个客户端的一行，而不是每个客户端的多行。

这是 tblClient 和 tblServices 表的快速浏览：

这些是我目前的结果：

这是我想要的结果：

我写了两个查询，两者都给出了当前结果，而不是我想要的结果：

SELECT 
    c.ClientID, CreateDate,
    MAX (CASE WHEN c.ServiceID = 1 THEN 1 ELSE 0 END) AS ‘Kitchen’,
    MAX (CASE WHEN c.ServiceID = 2 THEN 1 ELSE 0 END) AS ‘Living Room’,
    MAX (CASE WHEN c.ServiceID = 3 THEN 1 ELSE 0 END) AS ‘Dining Room’,
    MAX (CASE WHEN c.ServiceID = 4 THEN 1 ELSE 0 END) AS ‘Family Room’
FROM 
    tblClient c 
LEFT JOIN 
    s.tblServices s ON s.ServiceID = s.ServiceID
GROUP BY
    c.ClientID, CreateDate, c.ServiceID 

SELECT 
    c.ClientID, CreateDate,
    (CASE WHEN c.ServiceID = 1 THEN 1 ELSE 0 END) AS ‘Kitchen’,
    (CASE WHEN c.ServiceID = 2 THEN 1 ELSE 0 END) AS ‘Living Room’,
    (CASE WHEN c.ServiceID = 3 THEN 1 ELSE 0 END) AS ‘Dining Room’,
    (CASE WHEN c.ServiceID = 4 THEN 1 ELSE 0 END) AS ‘Family Room’
FROM 
    tblClient c 
LEFT JOIN 
    s.tblServices s ON s.ServiceID = s.ServiceID
GROUP BY
    c.ClientID, CreateDate, 
    CASE WHEN c.ServiceID = 1 THEN 1 ELSE 0 END,
    CASE WHEN c.ServiceID = 2 THEN 1 ELSE 0 END, 
    CASE WHEN c.ServiceID = 3 THEN 1 ELSE 0 END,
    CASE WHEN c.ServiceID = 4 THEN 1 ELSE 0 END

Answer 1

请求评论摘要：如果您希望每个客户和日期有一个结果行，则按客户和日期分组。

SELECT 
    c.clientid, c.createdate,
    MAX (CASE WHEN c.serviceid = 1 THEN 1 ELSE 0 END) AS "Kitchen",
    MAX (CASE WHEN c.serviceid = 2 THEN 1 ELSE 0 END) AS "Living Room",
    MAX (CASE WHEN c.serviceid = 3 THEN 1 ELSE 0 END) AS "Dining Room",
    MAX (CASE WHEN c.serviceid = 4 THEN 1 ELSE 0 END) AS "Family Room"
FROM tblclient c 
GROUP BY c.clientid, c.createdate
ORDER BY c.clientid, c.createdate;