SQL插入如果值不存在
问题描述:
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
答
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)
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