SQL Server：行为每月，列为年

我是一个试图按年份整齐地分隔数据的人，下面的查询实现了这一点，但是，date列（YYYYMM）显示了每年的每个月。因此，除了相应年份的行外，大多数行的每个年度列都是零

SELECT      
    DATEFROMPARTS(YEAR(l.Date), MONTH(l.Date), 01) AS YYYYMM,
    SUM(CASE WHEN l.State ='UT' AND YEAR(l.Date) = '2018' THEN 1 ELSE 0 END) AS 'UT - 2018',
    SUM(CASE WHEN l.State ='UT' AND YEAR(l.Date) = '2019' THEN 1 ELSE 0 END) AS 'UT - 2019',
    SUM(CASE WHEN l.State ='UT' AND YEAR(l.Date) = '2020' THEN 1 ELSE 0 END) AS 'UT - 2020',
    SUM(CASE WHEN l.State ='AZ' AND YEAR(l.Date) = '2018' THEN 1 ELSE 0 END) AS 'AZ - 2018',
    SUM(CASE WHEN l.State  ='AZ' AND YEAR(l.Date) = '2019' THEN 1 ELSE 0 END) AS 'AZ - 2019',
    SUM(CASE WHEN l.State ='AZ' AND YEAR(l.Date) = '2020' THEN 1 ELSE 0 END) AS 'AZ - 2020',
    SUM(CASE WHEN l.State ='NV' AND YEAR(l.Date) = '2020' THEN 1 ELSE 0 END) AS 'NV - 2020'
FROM
    dbo.list AS l,
    dbo.StatusLogs AS sl
WHERE
    sl.ListId = l.Id
GROUP BY    
    DATEFROMPARTS(YEAR(l.Date), MONTH(l.Date), 01)
ORDER BY    
    DATEFROMPARTS(YEAR(l.Date), MONTH(l.Date), 01)

我想做的是只做12行（每个月1行）。像这样：

MM       UT - 2018     ....     NV - 2020
Jan        10                     5
Feb        5                      8
...
Dec        6                      7

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学会使用正确、明确、标准、可读的连接语法

然后，修复方法是只需通过更改

组并选择

：

 SELECT MONTH(l.Date) AS month,
        SUM(CASE WHEN l.State ='UT' AND YEAR(l.Date) = 2018 THEN 1 ELSE 0 END) AS [UT - 2018],
        SUM(CASE WHEN l.State ='UT' AND YEAR(l.Date) = 2019 THEN 1 ELSE 0 END) AS [UT - 2019],
        SUM(CASE WHEN l.State ='UT' AND YEAR(l.Date) = 2020 THEN 1 ELSE 0 END) AS [UT - 2020],
        SUM(CASE WHEN l.State ='AZ' AND YEAR(l.Date) = 2018 THEN 1 ELSE 0 END) AS [AZ - 2018],
        SUM(CASE WHEN l.State  ='AZ' AND YEAR(l.Date) = 2019 THEN 1 ELSE 0 END) AS [AZ - 2019],
        SUM(CASE WHEN l.State ='AZ' AND YEAR(l.Date) = 2020 THEN 1 ELSE 0 END) AS [AZ - 2020],
        SUM(CASE WHEN l.State ='NV' AND YEAR(l.Date) = 2020 THEN 1 ELSE 0 END) AS [NV - 2020]
 FROM dbo.list l JOIN
      dbo.StatusLogs sl
      ON sl.ListId = l.Id
 GROUP BY MONTH(l.Date)
 ORDER BY MONTH(l.Date);

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我还删除了一堆单引号。单引号只能用于日期和字符串常量

YEAR（）

返回一个数字，因此比较应该是一个数字。列别名实际上不需要转义，但如果名称不一致，则使用方括号。单引号将列名与值混淆。

Beautiful！非常感谢-在ANSI-92 SQL标准中（25多年前），旧式的逗号分隔表列表样式被正确的ANSI

JOIN

语法所取代，因此不鼓励使用它