SQL插入如果值不存在

所以我需要插入值到表中，但如果这些值存在，我希望我的脚本不能插入任何东西。我几乎已经解决了这个问题，但是我的插入语句最终被卡住了。SQL插入如果值不存在

DECLARE @billableitemID int; 
set @billableitemid = (select billableitemID from dbo.treatment where 
@billableitemid=treatment.id) 
set @billableitemID = 256 



CREATE TABLE #MembershipBenefitItem 
    (BenefitID int , 
     BillableItemTypeID int , 
     BillableItemID int 
    ) 

INSERT INTO #MembershipBenefitItem 
    (BenefitID , 
     BillableItemTypeID , 
     BillableItemID 
    ) 

VALUES (23450,1,@billableitemid), 
(57256,1,@billableitemid) 

select m.* from #MembershipBenefitItem AS M 
left join membershipbenefititem AS M1 on m.billableitemid= m1.billableitemid 
and m.billableitemtypeid= m1.billableitemtypeid 
and m.benefitid= m1.benefitID 
and [email protected] and M1.billableitemtypeID=1 and 
M1.benefitID IN(23450,57256) 
where M1.ID is null 

INSERT INTO MembershipBenefitItem 
    (BenefitID, 
     BillableItemTypeID, 
     BillableItemID 
    ) 

select m.BenefitID, m.BillableItemTypeID, m.BillableItemID from 
#MembershipBenefitItem AS M 
left join membershipbenefititem AS M1 on m.billableitemid= m1.billableitemid 
and m.billableitemtypeid= m1.billableitemtypeid 
and m.benefitid= m1.benefitID 
and [email protected] and M1.billableitemtypeID=1 and 
M1.benefitID IN(23450,57256) 
where M1.ID is null 



DROP TABLE #MembershipBenefitItem

来源

2017-06-01 nick toppi

另一种方式做这样的事情会在合并声明。只是一个想法。通常虽然这用于如果存在更新其他插入 –

你卡在什么？ –

'Where ...并且不存在（键上的相关子查询）' – xQbert

这看起来像使用Merge语句的好例子。

https://docs.microsoft.com/en-us/sql/t-sql/statements/merge-transact-sql

它看起来是这样的：

MERGE MembershipBenefitItem AS trg 
USING #MembershipBenefitItem AS src 
ON src.BillableItemID = trg.BillableItemID --and other join conditions 
WHEN NOT MATCHED BY TARGET THEN 
INSERT (col1, col2, col3) -- this will be inserted into trg table 
VALUES (src.val1, src.val2, src.val3)

来源

2017-06-01 20:08:46 NoSaidTheCompiler

SQL插入如果值不存在

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