Merge,依据查询结果更新字段

依据另一个表的查询结果，更新当前表，可以使用merge关键字

依据考核表中统计的考核结果，更新工资表中的考核值。

Merge Into tr_salary p 
Using 
(Select staff_id,sum(reward_sum) As reward_goods From tp_check_goods Group By staff_id) np --
On (p.staff_id=np.staff_id )
when matched then 
update set p.reward_goods = np.reward_goods 
Where dept_Id='02' And p_year=2015 And p_month=6 --