oracle merge into 的用法详解+实例

Posted on 2009-06-18 16:10 林光炎 阅读(1389) 评论(0)  编辑  收藏 所属分类: ORACLE
oracle merge into 的用法详解+实例

作用:merge into 解决用B表跟新A表数据,如果A表中没有,则把B表的数据插入A表;


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 ! ]


merge into tfa_alarm_act_nms a
from tfa_alarm_status) b
on (a.fp0=b.fp0 and a.fp1=b.fp1 and a.fp2=b.fp2 and a.fp3=b.fp3)
when matched then update set a.redefine_severity=b.redefine_severity
when not matched then insert (a.fp0,a.fp1,a.fp2,a.fp3,a.org_severity,a.redefine_severity,a.event_time
values (b.fp0,b.fp1,b.fp2,b.fp3,b.REDEFINE_SEVERITY,b.redefine_severity,sysdate,7777778);

作用:利用表 tfa_alarm_status跟新表tfa_alarm_act_nms 的b.redefine_severity条件是a.fp0=b.fp0 and a.fp1=b.fp1 and a.fp2=b.fp2 and a.fp3=b.fp3,如果tfa_alarm_act_nms表中没有该条件的数据就插入。


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