SQL Server中一行中列的平均值除以零異常

Question

我有一些代碼用於計算表中某一行的平均值。問題是，現在的MinTwee，MinEen，nul，PlusEen和PlusTwee總和（是列名）等於零，它由零異常（什麼是正常的，當然）給了我一個鴻溝。你怎麼能保護它呢？如果總和等於零，那麼平均值也等於該行的零。我使用SQL Server 2014

select top 5 
    id, mintwee, mineen, nul, pluseen, plustwee, naam 
from 
    topic 
where 
    CategorieID = 7 and verwijderd = 0 
order by 
    round(cast((mintwee * (-2) + mineen * (-1) + nul * 0 + pluseen * 1 + PlusTwee * 2) as float)/(MinTwee + MinEen + nul + PlusEen + PlusTwee), 1) desc, creatie desc 

Answer 1

可以測試值爲0時，與

select top 5 id, mintwee, mineen, nul, pluseen, plustwee, naam 
from topic 
where CategorieID = 7 and verwijderd = 0 
order by 
    case when (MinTwee + MinEen + nul + PlusEen + PlusTwee) = 0 then creatie 
    else 
    round(cast((mintwee * (-2) + mineen * (-1) + nul * 0 + pluseen * 1 + PlusTwee * 2) as float)/(MinTwee + MinEen + nul + PlusEen + PlusTwee), 1) 
    end 
    desc, 
    creatie desc 

Answer 2

我想，以避免錯誤的最簡單方法是nullif()的情況下：

order by 
    coalesce(round(cast((mintwee * (-2) + mineen * (-1) + nul * 0 + pluseen * 1 + PlusTwee * 2) as float)/
      nullif(MinTwee + MinEen + nul + PlusEen + PlusTwee, 0), 1), 0) desc, 
    creatie desc