Question

我有这样的出勤表：

Student_id   attendance_date    status
-----------  ----------------   ---------
       1     1/8/2014          Present
       2     1/8/2015          Absent
       1     2/8/2014          Present
       2     2/8/2015          Present
       1     3/8/2014          Present
       2     3/8/2015          Present

预期输出为：

  Student_ id   1/8/2014      2/8/2014     3/8/2014
 -------------  ---------     ---------   ----------
         1     present         present      present
         2     absent          present      present

请帮助我获得预期的输出.....

Answer 1

您需要创建一个过程并使用Dynamic Pivot，如下所示。

DECLARE @dates NVARCHAR(MAX)
DECLARE @query AS NVARCHAR(MAX)

--Get all the dates to pivot
SELECT @dates = ISNULL(@dates  + ',','') 
       + QUOTENAME(attendance_date)
FROM (SELECT DISTINCT attendance_date FROM attendance) AS attendance 

--Construct the dynamic pivot query

SET @query = 
  N'SELECT status, ' + @dates + '
    FROM attendance
    PIVOT(MAX(status) 
          FOR dates IN (' + @dates + ')) AS pivotTable'

-- excecute the dynamic query

EXEC sp_executesql @query

Answer 2

可能是这个作品

SELECT   t.[user_id], t.[attendance_date],t.[status] 
     FROM    Attendance t 
 PIVOT   ( MIN(status) 
      FOR attendance_date IN ([1/8/2014],[2/8/2014],[3/8/2014]) ) pvt;

如何在SQL Server中将列转换为行

2 个答案: