MSSQL 插入数据时候，如果存在则更新的方法分享

ժҪ:
下文讲述MSSQL中，插入数据时，如果存在则更新,否则就插入数据的方法分享
实验环境:sql server 2017
mssql中，我们可以采用 MERGE INTO 关键字实现此功能，
当两者匹配成功，则运行***语句，否则运行其它语句，达到插入数据时的判断操作，
具体操作方法如下所示:

create table [maomao365.com] (keyId int identity, info varchar(80) ) go insert into [maomao365.com] (info)values('sqlblog'), ('sqlserver'),('maomao365.com')  ---merge into实现如果存在，则更新 ---如果不存在，则删除 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]

转自：

http://www.maomao365.com/?p=9679