update user_a a set user_info=(select user_info2 from user_b b
where a.user_id=b.user_id)
where exists (select 1 from user_b c where a.user_id=c.user_id);
where a.user_id=b.user_id)
where exists (select 1 from user_b c where a.user_id=c.user_id);
update user_a set user_a.user_info=user_b.user_info2
where user_b.user_id = 1;
where a.user_id=b.user_id );
where A.user_id=B.user_id)
where user_a.user_id = 1;of course,
if user_id's type is varchar2 then
user_a.user_id = '1';
try?
where a.user_id=b.user_id and user_b.user_id = 1)
where A.user_id=B.user_id)
where A.user_id = 1;