Question

如何解决该错误：

MERGE语句尝试多次更新或删除同一行。当目标行与多个源行匹配时，就会发生这种情况。 MERGE语句不能多次更新/删除目标表的同一行。优化ON子句以确保目标行最多匹配一个源行，或使用GROUP BY子句对源行进行分组。

merge CARD_ALERTS as t
using @tblAlerts as s
on (t.Id = s.AlertId and t.CardId = s.CardId)
when not matched by target
    then insert(Id, ExternalCodeHolder, CardId, IsCardOwner, IBAN, PAN, MinAmount, Currency, ByEmail, BySMS, IssueDate, IsActive)
        values(s.AlertId, s.ExternalCodeHolder, s.CardId, s.IsCardOwner, s.IBAN, s.PAN, s.MinAmount, s.Currency, s.ByEmail, s.BySMS, getdate(), 1)
when matched 
    then update set t.ByEmail = s.ByEmail, t.BySMS = s.BySMS, IsActive = 1, t.MinAmount = s.MinAmount
when not matched by source and t.Id=@AlertId 
    then update set t.IsActive = 3

Answer 1

如错误消息和注释中所述，源表的多行对应于目标行中的同一行。

这将向您显示目标表的哪些行中源表中有多行尝试对其进行更新：

select t.Id,t.CardId,count(*) as [count]
from CARD_ALERTS as t
inner join @tblAlerts as s
on (t.Id = s.AlertId and t.CardId = s.CardId)
group by t.Id,t.CardId
having count(*)>1

这还将向您显示源表的多行：

select t.*,s.*
from CARD_ALERTS as t
inner join @tblAlerts as s on (t.Id = s.AlertId and t.CardId = s.CardId)
inner join
(
    select ca.Id,ca.CardId
    from CARD_ALERTS as ca
    inner join @tblAlerts as s
    on (ca.Id = s.AlertId and ca.CardId = s.CardId)
    group by ca.Id,ca.CardId
    having count(*)>1
)tkey on t.Id=tkey.Id and t.CardId=tkey.CardId

如何解决此SQL特定的合并问题

1 个答案: