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 prev

Answer 1

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

SELECT *
FROM TableA, TableB
WHERE TableA.PrimaryKey(+) = TableB.ForeignKey

is equivalent to

SELECT *
FROM TableA
RIGHT OUTER JOIN TableB
  ON (TableA.PrimaryKey = TableB.ForeignKey)