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  • Sql中的Merge和output

    先看merge,

    不用merge时:

    --更新
    update TA
        set ColA=isnull((select top 1 Value from TB where TB.UserId=TA.UserId and TB.TypeName=@val),0)
        where DATEDIFF(day,[Date],@day)=0
    --插入没有的数据
    insert into TA 
        select newid(),UserId,@day,0,0,Value from TB 
        where not exists (select UserId from TA where TA.UserId=TB.UserId and DATEDIFF(day,[Date],@day)=0) 
            and TypeName=@val

    用Merge:

    merge TA as a
    using (select * from TB where TypeName=@val) as b
    on b.UserId=a.UserId
    when matched then update set a.ColA=b.Value
    when not matched then insert values(newid(),UserId,@day,0,0,Value)
    when not matched by source then update set a.ColA=0;
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  • 原文地址:https://www.cnblogs.com/icyJ/p/4609561.html
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