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  • oracle中行转列操作

    数据准备阶段:

    CREATE TABLE CC  (Student NVARCHAR2(2),Course NVARCHAR2(2),Score INT); 

    INSERT into CC   
    select N'张三',N'语文',78 from dual union all  
    select N'张三',N'数学',87 from dual union all  
    select N'张三',N'英语',82 from dual union all  
    select N'张三',N'物理',90 from dual union all  
    select N'李四',N'语文',65 from dual union all  
    select N'李四',N'数学',77 from dual union all  
    select N'李四',N'英语',65 from dual union all  
    select N'李四',N'物理',85 from dual ;  
    commit; 

    操作如下:

    方法一、

    select 
    student,
    sum(decode(course,'语文',score)) 语文,
    sum(decode(course,'数学',score)) 数学,
    sum(decode(course,'英语',score)) 英语,
    sum(decode(course,'物理',score)) 物理,
    sum(score)
    from cc group by student;

     方法二、

    SELECT KIN.*,  
      KIN.a+KIN.b+KIN.c+KIN.d AS TOTAL  
    FROM  
      (SELECT   *  
      FROM CC PIVOT ( MAX(SCORE) FOR COURSE IN ('语文' AS A , '数学' AS B, '英语' AS C,'物理' AS D) )  
      ) KIN; 

    方法三、

    select 
    student,
    sum(case when course = '语文' then score else 0 end )语文,
    sum(case when course = '数学' then score else 0 end )数学,
    sum(case when course = '英语' then score else 0 end )英语,
    sum(case when course = '物理' then score else 0 end )物理
    from cc group by student;

    完。

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  • 原文地址:https://www.cnblogs.com/hello-wei/p/10283527.html
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