What does (+) do in Oracle SQL?

Question

I'm using Oracle SQL Developer to query an Oracle DB (not sure which version it is) and I'm going to use the SQL I make for a Crystal report. Many of the reports the previous developers have written don't use JOIN keywords to make the joins (and I'm not too familiar with JOIN keywords as a result).

Many of the joins they make are made in the WHERE statement. I'll notice something like this.

Select * From TableA, TableB WHERE TableA.PrimaryKey(+) = TableB.ForeignKey

My question is concerning the (+). What purpose does it serve and how do I use it in my code?

Answer 1

It is not recommended. See this previous answer

http://stackoverflow.com/questions/1193654/different-between-oracles-plus-notation-over-ansi-join-notation

Answer 2

right outer join

Answer 3

That represents a "right outer join" (right because the '=' is on the right side of the '+').