替换一个表中的数据的SQL怎么写

[F10]

SQL Server 2000下，有两个数据库db1，db2，db1中有表table1，db2中有表table2。
table1中有字段field1,field2,field3
table2中有字段field4,field5,field6
用SQL语句怎么样在table1.field1=table2.field4的条件下实现将field1的内容更新成field3，field2更新成field4。

[愉快的登山者]

update table1 set field1 = field3, field2 = table2.field4
from table2
where table1.field1 = table2.field4

[aierong]

update table1 set field1 = field3, field2 = a.field4
from db2..table2 as a
where table1.field1 = a.field4

[aierong]

update table1 set a.field1 = a.field3, a.field2 = b.field4
from table1 as a join db2..table2 as b on a.field1=b.field4

[antoversky]

update table1 set a.field1 = a.field3, a.field2 = b.field4
from 服务器名.db1.dbo.table1 a,服务器名.db2.dbo.table2
where a.field1=b.field4