我的表格有以下列:
roll no | subject1 | subject2 | subject3 | subject4 | subject5 | subject6
1 | 10 | 12 | 13 | 9 | 15 | 16
2 | 12 | 14 | 10 | 16 | 19 | 13
3 | 10 | 12 | 13 | 18 | 12 | 15
4 | 14 | 12 | 13 | 7 | 11 | 17
现在我需要这种格式的数据:
Roll no | SubjectName | Marks
1 | subject1 | 10
1 | subject2 | 12
1 | subject3 | 13
1 | subject4 | 9
1 | subject5 | 15
1 | subject6 | 16
2 | subject1 | 12
2 | subject2 | 14
2 | subject3 | 10
2 | subject4 | 16
2 | subject5 | 19
2 | subject6 | 13
3 | subject1 | 10
3 | subject2 | 12
3 | subject3 | 13
3 | subject4 | 18
3 | subject5 | 12
3 | subject6 | 15
4 | subject1 | 14
4 | subject2 | 12
4 | subject3 | 13
4 | subject4 | 7
4 | subject5 | 11
4 | subject6 | 17
如您所见，我想将列显示为行
谢谢
最佳答案
如果您的数据库支持UNPIVOT ，你可以使用它。
如果没有，您可以使用UNION ALL:
SELECT roll_no, 'subject1' AS SubjectName, subject1 AS Marks FROM yourtable
UNION ALL
SELECT roll_no, 'subject2', subject2 FROM yourtable
UNION ALL
SELECT roll_no, 'subject3', subject3 FROM yourtable
UNION ALL
SELECT roll_no, 'subject4', subject4 FROM yourtable
UNION ALL
SELECT roll_no, 'subject5', subject5 FROM yourtable
UNION ALL
SELECT roll_no, 'subject6', subject6 FROM yourtable
UNION ALL
SELECT roll_no, 'subject7', subject7 FROM yourtable
关于SQL查询将列转换为行，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/10465668/