1、需求：找数据表objectTable 表中id为123456，没有就插入新记录，有就进行更新。

MERGE INTO  objectTable t 
USING ( select '123456' ID,'张三' Name  ) s  
ON (s.ID =t.ID )  
WHEN MATCHED THEN 
     UPDATE SET t.Name =s.Name  
WHEN NOT MATCHED THEN  
     INSERT (ID, Name) VALUES (s.ID,  s.Name);

2、目标表objectTable ,源表sourceTable ，对目标表中id相同的进行同步更新和插入。

MERGE INTO objectTable t 
USING (select 35 id from sourceTable) s  
ON (t.id = s.id)  
WHEN MATCHED THEN 
     UPDATE SET t.note =s.note--..... 
WHEN NOT MATCHED THEN  
     INSERT (id, note) VALUES (s.id,s.note);