MSSQLServer 纵向表转横向表 横向表转纵向表 行转列 列转行

MSSQLServer 纵向表转横向表  横向表转纵向表

建表语句及插入数据语句：

CREATE TABLE Test_y(

    [Name] [nchar](10) NULL,

    [Course] [nchar](10) NULL,

    [Grade] [int] NULL

) 

insert into Test_y values ('张三','语文',75);

insert into Test_y values ('张三','数学',80);

insert into Test_y values ('张三','英语',90);

insert into Test_y values ('李四','语文',90);

insert into Test_y values ('李四','数学',70);

insert into Test_y values ('李四','英语',80);



CREATE TABLE Test_x(

    [Name] [nchar](10) NULL,

    [语文] [nchar](10) NULL,

    [数学] [nchar](10) NULL,

    [英语] [nchar](10) NULL

)

insert into Test_x values('张三',75,80,90);

insert into Test_x values('李四',90,70,80);

纵向表转横向表效果展示：

纵向表转横向表 sql 语句如下：

方法一：

select * from Test_y;

select Name,

    sum(case Course when '语文' then Grade else 0 end) as 语文,

    sum(case Course when '数学' then Grade else 0 end) as 数学,

    sum(case Course when '英语' then Grade else 0 end) as 英语

    from Test_y group by Name;

方法二：

select * From Test_y

    pivot(sum(Grade) for Course IN ([语文],[数学],[英语]))

    AS Test_x;

横向表转纵向表效果展示:

横向表转纵向表 sql  语句如下：

方法一：

select * from Test_x;

select Name,'语文' as Course,语文 as Grade

    from Test_x union all

select Name,'数学' as Course,数学 as Grade

    from Test_x union all

select Name,'英语' as Course,英语 as Grade

    from Test_x  order by Name desc;

方法二：

select Name,Course,Grade from Test_x 

unpivot(Grade for Course in([数学],[英语],[语文]))as Test_y

最后谢谢 @漠北水獭 的提示。

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