意外“子查询返回多个值”

Question

表有这样的结构：grouptable将> lineGroupJoinTable> linesTable（名字被混淆的名字） 我有以下查询返回此错误：

Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, <, <= , >, >= or when the subquery is used as an expression.

的事情是，我期望，因为子查询是组，我不应该得到这个错误。我可能错过了一些东西。

UPDATE dbo.groupTable 
SET fieldToUpdate = CASE WHEN fieldToUpdate IS NULL THEN NULL ELSE 
(
    SELECT sumTable.fieldToSum FROM 
    dbo.groupTable gt 
    INNER JOIN 
    (
     SELECT lgjt.groupdId1, lgjt.groupdId2, SUM(lt.fieldToSum) as fieldToSum 
     FROM lineGroupJoinTable lgjt 
     INNER JOIN linesTable lt 
      ON 
       lt.fieldToSum IS NOT NULL AND lt.fieldToSum > 0 AND 
       lgjt.lineId1 = lt.lineId1 AND lgjt.lineId2 = lt.lineId2 
     GROUP BY lgjt.groupdId1, lgjt.groupdId2 

    ) sumTable 
    ON sumTable.groupdId1 = gt.groupdId1 AND sumTable.groupdId2 = gt.groupdId2 
) 
END 

这种变化还尝试以下建议，但返回相同的错误：

UPDATE dbo.groupTable 
SET fieldToUpdate = CASE WHEN fieldToUpdate IS NULL THEN NULL ELSE 
(
    SELECT SUM(sumTable.fieldToSum) FROM 
    dbo.groupTable gt 
    INNER JOIN 
    (
     SELECT lgjt.groupdId1, lgjt.groupdId2, SUM(lt.fieldToSum) as fieldToSum 
     FROM lineGroupJoinTable lgjt 
     INNER JOIN linesTable lt 
      ON 
       lt.fieldToSum IS NOT NULL AND lt.fieldToSum > 0 AND 
       lgjt.lineId1 = lt.lineId1 AND lgjt.lineId2 = lt.lineId2 
     GROUP BY lgjt.groupdId1, lgjt.groupdId2 

    ) sumTable 
    ON sumTable.groupdId1 = gt.groupdId1 AND sumTable.groupdId2 = gt.groupdId2 
    GROUP BY gt.groupdId1, gt.groupdId2 
) 
END 

Answer 1

可能是因为dbo.groupTable对组合ID1和ID2多重价值。我建议在id1和id2列上进行分组并做一个SUM，那样的话你只有1个结果。

UPDATE dbo.groupTable 
SET fieldToUpdate = CASE WHEN fieldToUpdate IS NULL THEN NULL ELSE 
(
    SELECT SUM(sumTable.fieldToSum) FROM 
    dbo.groupTable gt 
    INNER JOIN 
    (
     SELECT lgjt.id1, lgjt.id2, SUM(lt.fieldToSum) as fieldToSum 
     FROM lineGroupJoinTable lgjt 
     INNER JOIN linesTable lt 
      ON 
       lt.fieldToSum IS NOT NULL AND lt.fieldToSum > 0 AND 
       lgjt.id3 = lt.id3 AND lgjt.id4 = lt.id4 
     GROUP BY lgjt.id1, lgjt.id2 
    ) sumTable 
    ON sumTable.id1 = gt.id1 AND sumTable.id2 = gt.id2 
    GROUP BY gt.id1, gt.id2 
) 
END