一个数据库表向另一个数据库表插入数据

[yn00]

A表

pscode    effectdate    terminationdate  
1        
2 
3         

B表
pscode    effectdate    terminationdate  
1         2011-01-01     2012-01-12
2         2009-10-22     2012-06-10
3         2007-02-02     2011-11-05
4         2010-02-03     2010-10-11
5         2009-09-09     2012-01-05


请问我怎么把B表里的effectdate字段和terminationdate字段插入到A表中，不等于A表中pscode的不插入进来

[人生无悔]

update A
	set  effectdate=B.effectdate 
		,terminationdate=B.terminationdate 
	from B where A.pscode=B.pscode

[百年树人]

update a set a.effectdate=b.effectdate,a.terminationdate=b.terminationdate
from b
where a.pscode=b.pscode

[yn00]

谢谢两位。