Question

您好我有一个查询，可以获得每月和每年的事件总数我想要一个显示列中所有不同年份的结果您能否建议如何使这个查询动态化？

Expected Result:
Month      2013 2014 2015
January    8    0   12
February   9    6   10
March      12   1   9
April      10   13  27
May        9    22  15
June       27   4   20
July       15   12  22
August     20   2   2
September  22   5   10
October    10   8   12
November    0   7   0
December    0   15  0

查询

select DATENAME(MONTH,DateOpened) as Month,
   sum(case when year(DateOpened)  = '2015' then 1 else 0 end) as [2015],
   sum(case when year(DateOpened)  = '2014' then 1 else 0 end) as [2014]

from Incidents
group by DATENAME(MONTH,DateOpened), MONTH(DateOpened)
order by MONTH(DateOpened)

感谢您的帮助！

Answer 1

您可以使用PIVOT表运算符，如下所示：

SELECT *
FROM
(
  SELECT
    DATENAME(MONTH,DateOpened) as Month,
    DATENAME(Year,DateOpened) AS Year,
    DateOpened
  FROM Incidents
) AS t
PIVOT
(
  COUNT(DateOpened)
  FOR Year IN([2013], [2014], [2015])
) AS p;

SQL Fiddle Demo

如果您不需要编写年份列表并动态执行任何年份，则必须使用动态SQL动态运行查询，如下所示：

DECLARE @cols AS NVARCHAR(MAX);    
DECLARE @query AS NVARCHAR(MAX);

SELECT @cols = STUFF((SELECT distinct ',' +
                        QUOTENAME(DATENAME(Year,DateOpened))
                      from Incidents AS t
                      FOR XML PATH(''), TYPE
                     ).value('.', 'NVARCHAR(MAX)') 
                        , 1, 1, '');

SELECT @query = 'SELECT * , '+ @cols + '
FROM
(
  select 
    DATENAME(MONTH,DateOpened) as Month,
    DATENAME(Year,DateOpened) AS Year,
    DateOpened
  FROM Incidents
) AS t
PIVOT
(
  COUNT(DateOpened)
  FOR Year IN(' + @cols + ')' +
                  ') p';

  execute(@query);

SQL Fiddle Demo

这会给你这样的东西：

|     Month | 2014 | 2015 | 2014 | 2015 |
|-----------|------|------|------|------|
|     April |    0 |    3 |    0 |    3 |
|    August |    1 |    1 |    1 |    1 |
|  December |    1 |    0 |    1 |    0 |
|  February |    0 |    1 |    0 |    1 |
|      July |    1 |    1 |    1 |    1 |
| September |    1 |    0 |    1 |    0 |

请注意：两个查询都不会列出原始表上没有日期的任何月份。如果要列出计数为0的表中未列出的任何月份，则必须修改锚点查询，以便列出所有月份，即使未列出：

  SELECT
    m.Name as Month,
    i.Year,
    i.DateOpened 
  FROM
  (
   VALUES ('Janurary'), ('February'), ('March'),
          ('April'),    ('May'),      ('June'),
          ('July'),     ('August'),   ('September'),
          ('October'),  ('November'), ('December')
   ) AS m(Name) 
  LEFT JOIN
  (
    SELECT 
      DATENAME(MONTH,DateOpened) as Month,
      DATENAME(Year,DateOpened) AS Year,
      DateOpened 
    FROM Incidents 
  ) AS i ON i.Month = m.Name

并在动态查询中替换它。

Updated SQL Fiddle

这将为您提供零结果的缺失月份：

|     Month | 2014 | 2015 | 2014 | 2015 |
|-----------|------|------|------|------|
|  Janurary |    0 |    0 |    0 |    0 | <<
|  February |    0 |    1 |    0 |    1 |
|     March |    0 |    0 |    0 |    0 | <<
|     April |    0 |    3 |    0 |    3 |
|       May |    0 |    0 |    0 |    0 | <<
|      June |    0 |    0 |    0 |    0 | <<
|      July |    1 |    1 |    1 |    1 |
|    August |    1 |    1 |    1 |    1 |
| September |    1 |    0 |    1 |    0 |
|   October |    0 |    0 |    0 |    0 | <<
|  November |    0 |    0 |    0 |    0 | <<
|  December |    1 |    0 |    1 |    0 |

Answer 2

一个像这样的简单创建表..

  CREATE TABLE #tmpIncidents
  (
    IncidentName NVARCHAR(50)
    , DateOpened DATETIME
  )

  INSERT INTO #tmpIncidents (IncidentName,DateOpened) VALUES 
  ('Test1',GETDATE()),
  ('Test1',DATEADD(YEAR,-1,GETDATE())),
  ('Test1',DATEADD(YEAR,-2,GETDATE())),
  ('Test1',DATEADD(YEAR,2,GETDATE())),
  ('Test1',DATEADD(YEAR,1,GETDATE())),
  ('Test1',DATEADD(YEAR,3,GETDATE()))

然后是多年的构建查询

  DECLARE @columnVar NVARCHAR(4000)

  SELECT @columnVar =
      (SELECT DISTINCT
            '[' + CONVERT(NVARCHAR(150),DATEPART(YEAR,DateOpened)) + '],' AS [text()]
      FROM #tmpIncidents
      FOR XML PATH('')
      )
  SET @columnVar = (SELECT LEFT(@columnVar,LEN(@columnVar)-1))
  --SELECT @columnVar --so you can see how it looks..

然后执行您的查询。

  EXEC ('
  SELECT
    pv.*
  FROM 
  (
    SELECT DATENAME(MONTH,DateOpened) AS [DateName], DATEPART(YEAR,DateOpened) AS [YEAR], IncidentName FROM #tmpIncidents
  ) src
  PIVOT
  (
    COUNT(IncidentName)
    FOR [YEAR] IN (' + @columnVar + ')
  ) pv;
  ')

SQL Query生成动态列

2 个答案: