sql的行转列(PIVOT)与列转行(UNPIVOT)

浅浅的花香味﹌ 2022-01-29 07:07 303阅读 0赞

**在做数据统计的时候，行转列，列转行是经常碰到的问题。case when方式太麻烦了，而且可扩展性不强，可以使用 PIVOT，UNPIVOT比较快速实现行转列，列转行，而且可扩展性强**

#### 一、行转列 ####

**1、测试数据准备**

CREATE  TABLE [StudentScores]
    (
       [UserName]         NVARCHAR(20),        --学生姓名
       [Subject]          NVARCHAR(30),        --科目
       [Score]            FLOAT,               --成绩
    )
    
    INSERT INTO [StudentScores] SELECT '张三', '语文', 80
    INSERT INTO [StudentScores] SELECT '张三', '数学', 90
    INSERT INTO [StudentScores] SELECT '张三', '英语', 70
    INSERT INTO [StudentScores] SELECT '张三', '生物', 85
    INSERT INTO [StudentScores] SELECT '李四', '语文', 80
    INSERT INTO [StudentScores] SELECT '李四', '数学', 92
    INSERT INTO [StudentScores] SELECT '李四', '英语', 76
    INSERT INTO [StudentScores] SELECT '李四', '生物', 88
    INSERT INTO [StudentScores] SELECT '码农', '语文', 60
    INSERT INTO [StudentScores] SELECT '码农', '数学', 82
    INSERT INTO [StudentScores] SELECT '码农', '英语', 96
    INSERT INTO [StudentScores] SELECT '码农', '生物', 78

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM1NTMxNTQ5_size_16_color_FFFFFF_t_70]

**2、行转列sql**

SELECT * FROM [StudentScores] /*数据源*/
    AS P
    PIVOT 
    (
        SUM(Score/*行转列后 列的值*/) FOR 
        p.Subject/*需要行转列的列*/ IN ([语文],[数学],[英语],[生物]/*列的值*/)
    ) AS T

**执行结果：**  
![在这里插入图片描述][20190521121615824.png]

#### 二、列转行 ####

**1、测试数据准备**

CREATE TABLE ProgrectDetail
    (
        ProgrectName         NVARCHAR(20), --工程名称
        OverseaSupply        INT,          --海外供应商供给数量
        NativeSupply         INT,          --国内供应商供给数量
        SouthSupply          INT,          --南方供应商供给数量
        NorthSupply          INT           --北方供应商供给数量
    )
    
    INSERT INTO ProgrectDetail
    SELECT 'A', 100, 200, 50, 50
    UNION ALL
    SELECT 'B', 200, 300, 150, 150
    UNION ALL
    SELECT 'C', 159, 400, 20, 320
    UNION ALL

![在这里插入图片描述][2019052112163156.png]

**2、列转行的sql**

SELECT P.ProgrectName,P.Supplier,P.SupplyNum
    FROM 
    (
        SELECT ProgrectName, OverseaSupply, NativeSupply,
               SouthSupply, NorthSupply
         FROM ProgrectDetail
    )T
    UNPIVOT 
    (
        SupplyNum FOR Supplier IN
        (OverseaSupply, NativeSupply, SouthSupply, NorthSupply )
    ) P

**执行结果：**

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM1NTMxNTQ5_size_16_color_FFFFFF_t_70 1]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM1NTMxNTQ5_size_16_color_FFFFFF_t_70]: /images/20220129/46e791d3afcd42ad9e196db39095c92a.png
[20190521121615824.png]: /images/20220129/6f6e5dd9803d413582996f454750a118.png
[2019052112163156.png]: /images/20220129/8aca656deffa4bdca33f91dbf6aba0b3.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM1NTMxNTQ5_size_16_color_FFFFFF_t_70 1]: /images/20220129/3bbd5e035e9b46c997964f7e6c19a4ee.png