Question

我正在使用SQL'Pivot'来显示每月的出勤率，但要面对Error Invalid column name 'DayValue'. Invalid column name 'Stu_Status'。

M使用以下SQL查询

Select 
       StudentID, Stu_Status, DAY([AttandanceDate]) as [DayValue] 
  From tbl_Students_Attandance as studAttd
 PIVOT (Max([Stu_Status])
   FOR [DayValue] IN ([1], [2], [3], [4],[5], [6], [7], [8], [9],
       [10],  [11], [12], [13], [14],[15], [16], [17], [18], [19],
       [20], [21], [22], [23], [24],[25], [26], [27], [28], [29],[30])
       ) AS Piviottable;

使用下表设计

SQL Table Design Image

要达到以下效果 Required result Image

Answer 1

您可以改用有条件的聚合：

select StudentID, max(case when day(AttandanceDate) = 1 then Stu_Status end) as [1],
       . . . 
from  tbl_Students_Attandance as studAttd
group by StudentID;

但是，我怀疑这还需要提及year()以匹配当前year和month的出勤率。

Answer 2

请尝试：查询中的问题很少，因此如果可以，请比较两个查询并尝试了解您刚刚错过的内容

SELECT StudentID, [1], [2], [3], [4],[5], [6], [7], [8], [9],
       [10],  [11], [12], [13], [14],[15], [16], [17], [18], [19],
       [20], [21], [22], [23], [24],[25], [26], [27], [28], [29],[30], [31]
FROM(
    Select 
       StudentID, Stu_Status, DAY([AttandanceDate]) as [DayValue] 
  From tbl_Students_Attandance
) AS studAttd
PIVOT
(
    MAX(Stu_Status)
    FOR [DayValue] IN ([1], [2], [3], [4],[5], [6], [7], [8], [9],
       [10],  [11], [12], [13], [14],[15], [16], [17], [18], [19],
       [20], [21], [22], [23], [24],[25], [26], [27], [28], [29],[30], [31])
) AS pvt

使用数据透视表显示学生出勤率

2 个答案: