1,纵表转横表
纵表结构 Table_A:
转换后的结构:
纵表转横表的SQL示例:
SELECT Name ,
SUM(CASE WHEN Course = N‘语文‘ THEN Grade
ELSE 0
END) AS Chinese ,
SUM(CASE WHEN Course = N‘数学‘ THEN Grade
ELSE 0
END) AS Mathematics ,
SUM(CASE WHEN Course = N‘英语‘ THEN Grade
ELSE 0
END) AS English
FROM dbo.Table_A
GROUP BY Name
2,横表转纵表
横表结构Table_B:
转换后的表结构:
横表转纵表的SQL示例:
SELECT Name ,
‘Chinese‘ AS Course ,
Chinese AS Score
FROM dbo.Table_B
UNION ALL
SELECT Name ,
‘Mathematics‘ AS Course ,
Mathematics AS Score
FROM dbo.Table_B
UNION ALL
SELECT Name ,
‘English‘ AS Course ,
English AS Score
FROM dbo.Table_B
ORDER BY Name ,
Course DESC
时间: 2024-10-31 17:15:49