SQL Server之縱表與橫表互轉

1，縱表轉橫表

縱表結構 Table_A：

轉換后的結構：

縱表轉橫表的SQL示例：

SELECT  Name ,
        SUM(CASE WHEN Course = N'語文' THEN Grade
                 ELSE 0
            END) AS Chinese ,
        SUM(CASE WHEN Course = N'數學' THEN Grade
                 ELSE 0
            END) AS Mathematics ,
        SUM(CASE WHEN Course = N'英語' THEN Grade
                 ELSE 0
            END) AS English
FROM    dbo.Table_A
GROUP BY Name

2，橫表轉縱表

橫表結構Table_B：

轉換后的表結構：

橫表轉縱表的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