Really basic query

Question

Hi,
I am a novice. I can't figure out what (+) means when it appears in statements like this: (the below statement is only representative)
select b.f_user_id, a.amount from t_accounts a, t_users b where
a.f_user_id(+) = b.f_user_id
and what abt
select b.f_user_id, a.amount from t_accounts a, t_users b where
a.f_user_id = b.f_user_id(+)
Whats the difference between the first and second usage?
Kindly bear with me if this is a really basic stuff.
Thanks

Answer 1

Hi,
I can't figure out what (+) means (+) is an outer join.
select b.f_user_id, a.amount from t_accounts a,
t_users b where
a.f_user_id(+) = b.f_user_idIt take all records of b table, even if join a.f_user_id = b.f_user_id is not verified. If join is not verified, a.amount value will be null.
select b.f_user_id, a.amount from t_accounts a,
t_users b where
a.f_user_id = b.f_user_id(+)It take all records of a table, even if join a.f_user_id = b.f_user_id is not verified. If join is not verified, b.f_user_id value will be null.
http://download-west.oracle.com/docs/cd/B10501_01/server.920/a96540/queries7.htm#2054625
Nicolas.