sql server 单行多列合并为一列
我有这样的桌子
Reg_No Student_Name Subject1 Subject2 Subject3 Subject4 Total
----------- -------------------- ----------- ----------- ----------- ----------- -----------
101 Kevin 85 94 78 90 347
102 Andy 75 88 91 78 332
从这里我需要创建一个临时表或这样的表:
From this I need to create a temp table or table like this:
Reg_No Student_Name Subject Total
----------- -------------------- ----------- -----------
101 Kevin 85 347
94
78
90
102 Andy 75 332
88
91
78
有没有办法在 SQL Server 中做到这一点?
Is there a way I can do this in SQL Server?
推荐答案
检查 this Fiddle
;WITH MyCTE AS
(
SELECT *
FROM (
SELECT Reg_No,
[Subject1],
[Subject2],
[Subject3],
[Subject4]
FROM Table1
)p
UNPIVOT
(
Result FOR SubjectName in ([Subject1], [Subject2], [Subject3], [Subject4])
)unpvt
)
SELECT T.Reg_No,
T.Student_Name,
M.SubjectName,
M.Result,
T.Total
FROM Table1 T
JOIN MyCTE M
ON T.Reg_No = M.Reg_No
如果您确实想要其余的 NULL 值，您可以尝试以下操作:
If you do want NULL values in the rest, you may try the following:
这是新的小提琴
这是代码:
;WITH MyCTE AS
(
SELECT *
FROM (
SELECT Reg_No,
[Subject1],
[Subject2],
[Subject3],
[Subject4]
FROM Table1
)p
UNPIVOT
(
Result FOR SubjectName in ([Subject1], [Subject2], [Subject3], [Subject4])
)unpvt
),
MyNumberedCTE AS
(
SELECT *,
ROW_NUMBER() OVER(PARTITION BY Reg_No ORDER BY Reg_No,SubjectName) AS RowNum
FROM MyCTE
)
SELECT T.Reg_No,
T.Student_Name,
M.SubjectName,
M.Result,
T.Total
FROM MyCTE M
LEFT JOIN MyNumberedCTE N
ON N.Reg_No = M.Reg_No
AND N.SubjectName = M.SubjectName
AND N.RowNum=1
LEFT JOIN Table1 T
ON T.Reg_No = N.Reg_No
相关文章