更新匹配文本数据类型的表

Question

我有下表

alt text http://img683.imageshack.us/img683/930/town.png

我想从匹配TownId的下表中更新其TownId。

alt text http://img269.imageshack.us/img269/6453/townid.png

表1的期望结果是

alt text http://img132.imageshack.us/img132/8184/townidupdaed.png

Answer 1

UPDATE  t1 
SET t1.townid=t2.townid
FROM table1 t1 
JOIN table2 t2 ON t1.town=t2.town