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  • Oracle视图

    create view t_myuser as
    select 
      ooo.*,
      decode(sign((select avg(score)-struts from t_user_score where ke='struts')),1,'是的,低于平均分',-1,'高于平均分','跟平均分持平') low_struts_avg,
      decode(sign((select avg(score)-spring from t_user_score where ke='spring')),1,'是的,低于平均分',-1,'高于平均分','跟平均分持平') low_srping_avg,
      decode(sign((select avg(score)-hibernate from t_user_score where ke='hibernate')),1,'是的,低于平均分',-1,'高于平均分','跟平均分持平') low_hibernate_avg,
      decode(sign((select avg(score)-oracle from t_user_score where ke='oracle')),1,'是的,低于平均分',-1,'高于平均分','跟平均分持平') low_oracle_avg
    from (
      select * from (
         (select user_name,ke,score from t_user_score)
      )
      pivot(
          sum(score)             -- 统计值
          for ke in ('struts' as struts,'spring' as spring,'hibernate' as hibernate,'oracle' as oracle)      -- 划分多少列
      )
    ) ooo
    
    select * from t_user_score
    
    -- 查询简单多了
    select * from t_myuser
    -- 条件查询
    select * from t_myuser where spring<40
    
    --试图view,数据能改吗?
    update t_myuser set struts=81 where spring<40
    update t_myuser set user_name='小陈' where spring<40
    select * from t_user_score
    select rowid,user_name from t_myuser
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  • 原文地址:https://www.cnblogs.com/yuchne/p/12920746.html
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