MERGE INTO [your table-name] [rename your table here]
USING ( [write your query here] )[rename your query-sql and using just like a table]
ON ([conditional expression here] AND [...]...)
WHEN MATHED THEN [here you can execute some update sql or something else ]
WHEN NOT MATHED THEN [execute something else here ! ]
使用注意点:
Merge Into执行时,会从using 搜出来的结果逐条与 on条件匹配,然后决定是update还是Insert。
所以using后面的sql没有查询到数据这个Merge Into语句是不会执行update和Insert操作的。
因此,单表操作时,只能写成两个sql先能生效
转载于:https://my.oschina.net/u/2552902/blog/543898