Mysql Union All返回表中没有记录的值

我想根据相关表的值分别显示重新提交和首次提交都是索赔类型

因此，我使用下面的查询分别获取这两条记录

SELECT ROUND(coalesce(SUM(c.ClaimNet), 0), 2) as net, 
       MAX(c.ClaimID), count(c.ClaimID) as claims, 
       MAX(h.TransactionDate) as TransactionDate, 
       'Resubmission' AS 'Claim Type' 
FROM Claim c 
LEFT OUTER JOIN ClaimHeader h on h.HeaderID = c.HeaderPKID 
INNER JOIN Resubmission r ON r.ClaimID = c.ClaimPKID WHERE h.HeaderType=2 

UNION ALL 

SELECT ROUND(coalesce(SUM(c.ClaimNet), 0), 2) as net, 
       MAX(c.ClaimID), count(c.ClaimID) as claims, 
       MAX(h.TransactionDate) as TransactionDate, 
      'First Submission' AS 'Claim Type' 
FROM Claim c 
LEFT OUTER JOIN ClaimHeader h on h.HeaderID = c.HeaderPKID 
WHERE ClaimPKID NOT IN 
         ( SELECT ClaimID FROM Resubmission GROUP BY ClaimID ) AND HeaderType=2

在上面的查询中，我使用UNIONALL从索赔表中获取数据。如果索赔表主键在重新提交表中用作外键，则它是重新提交索赔类型，如果它未在重新提交表中使用，则它是首次提交

我的问题是，尽管表中没有特定select查询的记录，但它返回空值并提及索赔类型。请参考下面的屏幕截图

试试这个：

select * 
from
(SELECT ROUND(coalesce(SUM(c.ClaimNet), 0), 2) as net, 
       MAX(c.ClaimID) claimid, count(c.ClaimID) as claims, 
       MAX(h.TransactionDate) as TransactionDate, 
       'Resubmission' AS 'Claim Type' 
FROM Claim c 
LEFT OUTER JOIN ClaimHeader h on h.HeaderID = c.HeaderPKID 
INNER JOIN Resubmission r ON r.ClaimID = c.ClaimPKID WHERE h.HeaderType=2 

UNION ALL 

SELECT ROUND(coalesce(SUM(c.ClaimNet), 0), 2) as net, 
       MAX(c.ClaimID), count(c.ClaimID) as claims, 
       MAX(h.TransactionDate) as TransactionDate, 
      'First Submission' AS 'Claim Type' 
FROM Claim c 
LEFT OUTER JOIN ClaimHeader h on h.HeaderID = c.HeaderPKID 
WHERE ClaimPKID NOT IN 
         ( SELECT ClaimID FROM Resubmission GROUP BY ClaimID ) AND HeaderType=2) claims
where claims.claims <> 0

试试这个：

select * 
from
(SELECT ROUND(coalesce(SUM(c.ClaimNet), 0), 2) as net, 
       MAX(c.ClaimID) claimid, count(c.ClaimID) as claims, 
       MAX(h.TransactionDate) as TransactionDate, 
       'Resubmission' AS 'Claim Type' 
FROM Claim c 
LEFT OUTER JOIN ClaimHeader h on h.HeaderID = c.HeaderPKID 
INNER JOIN Resubmission r ON r.ClaimID = c.ClaimPKID WHERE h.HeaderType=2 

UNION ALL 

SELECT ROUND(coalesce(SUM(c.ClaimNet), 0), 2) as net, 
       MAX(c.ClaimID), count(c.ClaimID) as claims, 
       MAX(h.TransactionDate) as TransactionDate, 
      'First Submission' AS 'Claim Type' 
FROM Claim c 
LEFT OUTER JOIN ClaimHeader h on h.HeaderID = c.HeaderPKID 
WHERE ClaimPKID NOT IN 
         ( SELECT ClaimID FROM Resubmission GROUP BY ClaimID ) AND HeaderType=2) claims
where claims.claims <> 0

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没有Group By的聚合始终返回一行，即使没有数据。为了避免这种情况，您可以简单地添加COUNT*>0：

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没有Group By的聚合始终返回一行，即使没有数据。为了避免这种情况，您可以简单地添加COUNT*>0：

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ROUNDcoalesceSUMc.ClaimNet，0，2是worng，roundsumcalescecc.ClaimNet，0，2是正确的，谢谢…但这不是问题oundcoalescesumc.ClaimNet，0，2是worng，roundsumcalescecc.ClaimNet，0，2是正确的，谢谢……但这不是一个问题。它可能有助于描述它是如何解决问题的。它可能有助于描述它是如何解决问题的。