Question

我的表有很多列，但只需要前两个

Mtype   join_date   Other
A   28/05/2014 00:00    xx
B   04/11/2014 00:00    xx
C   23/03/2007 00:00    xx
D   04/09/2013 00:00    xx
E   26/11/2014 00:00    xx
F   24/07/2011 00:00    xxx
G   28/05/2014 00:00    xx
A   20/06/2013 00:00    x
B   04/11/2014 00:00    x
C   20/06/2013 00:00    x

这是我想要的结果

+-------+---------+---------+---------+---------+---------+---------+--------+--------+--------+
| Mtype | 2015-03 | 2015-02 | 2015-01 | 2014-12 | 2014-11 | 2014-10 | 2014-9 | 2014-8 | 2014-7 |
+-------+---------+---------+---------+---------+---------+---------+--------+--------+--------+
| A     |      45 |       7 |      54 |     875 |      45 |       7 |     54 |    875 |     25 |
| B     |       7 |      78 |      78 |       7 |       7 |      78 |     78 |      7 |     78 |
| C     |     546 |       6 |      87 |       5 |      45 |       6 |     87 |      5 |     25 |
| D     |      54 |      78 |      54 |       8 |      54 |      78 |     54 |      7 |      7 |
| E     |      78 |      78 |       7 |      45 |      78 |      78 |      7 |     45 |      6 |
| F     |      46 |      54 |       6 |       8 |      46 |      54 |      6 |      8 |     75 |
| G     |      54 |      87 |      87 |       7 |      54 |      87 |     87 |     45 |      8 |
+-------+---------+---------+---------+---------+---------+---------+--------+--------+--------+

代码

DECLARE @cols NVARCHAR (MAX)
DECLARE @query NVARCHAR (MAX)
SELECT @cols = COALESCE (@cols + ',[' + CONVERT(VARCHAR(7), join_date, 120) + ']', 
          '[' + CONVERT(VARCHAR(7), join_date, 120) + ']')
           FROM    (SELECT DISTINCT CONVERT(VARCHAR(7), join_date, 120) as join_date FROM MD T0) PV  
           ORDER BY join_date DESC

SELECT @query = 'SELECT *
FROM
(
   SELECT Mtype, CONVERT(VARCHAR(7), join_date, 120) as join_date FROM MD T0
) AS t
PIVOT 
(
  COUNT(join_date) 
  FOR join_date IN( ' + @cols + ')' +
') AS p ;'

EXEC SP_EXECUTESQL @query

我遇到的问题是我只看到三列Mtype，（日期），（日期）取决于

ORDER BY join_date DESC
    +-------+---------+---------+
    | Mtype | 2015-09 | 2015-08 | 
    +-------+---------+---------+-
    | A     |      45 |       7 | 
    | B     |       7 |      78 | 
    | C     |     546 |       6 | 
    | D     |      54 |      78 | 
    | E     |      78 |      78 | 
    | F     |      46 |      54 | 
    | G     |      54 |      87 | 
    +-------+---------+---------+

这两列是DESC 2015-09和2015-08或ASC 1989-07和1990-05。我的问题是我的查询有什么问题，我只看到2个日期列而不是所有列（超过100个）。

Answer 1

如果你运行它会怎么样？

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

CREATE TABLE #VALS (VALS NVARCHAR(4000))

INSERT INTO #VALS
SELECT DISTINCT CONVERT(VARCHAR(7), join_date, 120) 
FROM MD T0
ORDER BY CONVERT(VARCHAR(7), join_date, 120)

SELECT @COLS = COALESCE(@COLS+', ','') + '[' + VALS + ']' FROM #VALS

SET @QUERY = '
;WITH CTE AS (
SELECT MTYPE, CONVERT(VARCHAR(7), join_date, 120) AS join_date, COUNT(*) AS RECORDS
FROM MD T0)
SELECT *
FROM CTE
PIVOT(SUM(RECORDS) FOR join_date IN ('+@cols+')) PIV'
EXEC SP_EXECUTESQL @query

PIVOT语句

1 个答案: