MSSQL 插入數據時候，若是存在則更新的方法分享

摘要:
下文講述MSSQL中，插入數據時，若是存在則更新,不然就插入數據的方法分享
實驗環境:sql server 2017 
mssql中，咱們能夠採用 MERGE INTO 關鍵字實現此功能，
當二者匹配成功，則運行***語句，不然運行其它語句，達到插入數據時的判斷操做，
具體操做方法以下所示: 

create table [maomao365.com] (keyId int identity, info varchar(80) ) go
insert into [maomao365.com] (info)values('sqlblog'), ('sqlserver'),('maomao365.com') ---merge into實現若是存在，則更新 ---若是不存在，則刪除
MERGE INTO [maomao365.com] a USING (SELECT 2 AS keyId_B, 'other' AS info_B ) b ON ( a.keyId = b.keyId_B) WHEN MATCHED THEN
UPDATE SET a.info= b.info_B --更新

WHEN NOT MATCHED THEN
INSERT (info) VALUES(b.info_B); ---插入

go
select * from [maomao365.com]
go MERGE INTO [maomao365.com] a USING (SELECT 20 AS keyId_B, 'new Info' AS info_B ) b ON ( a.keyId = b.keyId_B) WHEN MATCHED THEN
UPDATE SET a.info= b.info_B --更新

WHEN NOT MATCHED THEN
INSERT (info) VALUES(b.info_B); ---插入
go

select * from [maomao365.com]
go
truncate table [maomao365.com]
drop table [maomao365.com]

轉自：

 http://www.maomao365.com/?p=9679

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merge關鍵字實現增刪改