用笛卡尔积重写查询

Question

我不是开发人员，所以需要帮助重写这个查询没有内部连接，因为我认为这是核心问题。这段视频超过20秒。较小的块在一秒钟内运行。Pl的帮助。

select a.compID, b.InitialRT, b.VwRgts, b.UpdRgts, b.InsRgts, b.delRgts, b.Sscrnum , c.UserID
from tablecmpy a, tbldetrght b (nolock)
inner join tableuser c (nolock) on c.GroupID = b.UserId 
where b.RecType='G'  
and b.compID='[ALL]' 
and b.InitialRT+b.VwRgts+b.UpdRgts+b.InsRgts+b.delRgts > 0  

Answer 1

您已经在这里获得了笛卡尔连接(老式连接)from tablecmpy a, tbldetrght b (nolock)。尝试使用:

SELECT  a.compID, 
        b.InitialRT, 
        b.VwRgts, 
        b.UpdRgts, 
        b.InsRgts, 
        b.delRgts, 
        b.Sscrnum, 
        c.UserID
FROM tablecmpy a (nolock)
CROSS JOIN tbldetrght b (nolock)
INNER JOIN tableuser c (nolock) 
    ON c.GroupID = b.UserId 
WHERE b.RecType='G'  
    AND b.compID='[ALL]' 
    AND COALESCE(b.InitialRT,0) + 
        COALESCE(b.VwRgts,0) +
        COALESCE(b.UpdRgts,0) + 
        COALESCE(b.InsRgts,0) +
        COALESCE(b.delRgts,0) > 0 

我不知道在b.columns中是否有NULL，所以我添加了COALESCE来处理它们