sql update multiple values from sub-request

hi there !

i have a problem finding the syntax for an sql update of multiple values at the same time from a select sub-request on another table.

Here is what i mean :

field1, field2, field3, field4 from table 1
need to be updated by

new_field1, new_field2, new_field3, new_field4 from table 2

i only know how to update 1 value at a time, and straight from typing it in the sql code...

Could somebody help ?

Cheers

Terence