SQL Server中单行MERGE / upsert的语法

我试图做一个表单插入/更新，但所有的例子是有集。

任何人都可以修复我的语法：

MERGE member_topic ON mt_member = 0 AND mt_topic = 110 WHEN MATCHED THEN UPDATE SET mt_notes = 'test' WHEN NOT MATCHED THEN INSERT (mt_member, mt_topic, mt_notes) VALUES (0, 110, 'test') 

每个marc_s的解决scheme是将单行转换为子查询 – 这让我觉得MERGE命令并不是真正用于单行的upserts。

 MERGE member_topic USING (SELECT 0 mt_member, 110 mt_topic) as source ON member_topic.mt_member = source.mt_member AND member_topic.mt_topic = source.mt_topic WHEN MATCHED THEN UPDATE SET mt_notes = 'test' WHEN NOT MATCHED THEN INSERT (mt_member, mt_topic, mt_notes) VALUES (0, 110, 'test'); 

Answer 1

基本上，你是在正确的轨道上 – 但你错过了你想要合并数据的来源 – 尝试像这样：

 MERGE member_topic AS target USING someOtherTable AS source ON target.mt_member = source.mt_member AND source.mt_member = 0 AND source.mt_topic = 110 WHEN MATCHED THEN UPDATE SET mt_notes = 'test' WHEN NOT MATCHED THEN INSERT (mt_member, mt_topic, mt_notes) VALUES (0, 110, 'test') ; 

对于单行MERGE没有特殊的语法 – 您只需要使用适当的子句即可。 在ON子句中使用适当的条件，可以将源限制为单行 – 没有问题。

不要忘记后面的分号！ 没有开玩笑 – 这很重要！

看到这个博客文章是一个很好的介绍MERGE 。

Answer 2

我终于在SQL Server 2008中使用MERGE获得了Upsert语法。使用Jacob 想做的事（Upsert）：

 IF EXISTS(SELECT * FROM member_topic WHERE mt_member = 0 AND mt_topic = 110) BEGIN --update existing row UPDATE member_topic SET mt_notes = 'test' WHERE mt_member = 0 AND mt_topic = 110 END ELSE BEGIN --insert new row INSERT INTO member_topic (mt_member, mt_topic, mt_notes) VALUES (0, 110, 'test') END 

等效的MERGE语法是：

 MERGE member_topic USING ( VALUES (0, 110, 'test') ) AS foo (mt_member, mt_topic, mt_notes) ON member_topic.mt_member = foo.mt_member AND member_topic.mt_topic = foo.mt_topic WHEN MATCHED THEN UPDATE SET mt_notes = foo.mt_notes WHEN NOT MATCHED THEN INSERT (mt_member, mt_topic, mt_notes) VALUES (foo.mt_member, foo.mt_topic, foo.mt_notes) ; --A MERGE statement must be terminated by a semi-colon (;).