涉及两个表的Oracle更新语句（但不复制另一个表中的数据）

This might be hard to explain, but I have two tables:

create table UserInputMovie
(
movid varchar2(7),
MUcomment varchar2(50),
MUname varchar2(25),
MUrating number(2)
);

and

create table TempMProfiles
(
movid varchar2(7),
mname varchar2(25),
mdesc varchar2(80)
);

What I want to do here is make it so that I can update MUrating, MUcomment where the movid of TempMProfiles is the same as UserInputMovie.

Similar to a SELECT, you need a WHERE-condition to find matching rows:

update UserInputMovie
set <whatever>
where exists
 (
   select * 
   from TempMProfiles  
   where TempMProfiles.movid  = UserInputMovie.movid
 )