What is (+) at the end of the query?

Question

I'm quite new to oracle sql and just ran into a query that looks something like this

SELECT some_field
FROM some_table
WHERE some_other_field=some_value(+);

I simplified and annonimized the code, but im curious whats the (+) at the end. I don't remember seeing that in mssql world ever.

Please see my detailed answer here http://stackoverflow.com/a/28499208/3989608 — Lalit Kumar B, May 22 '15 at 08:28
Probably more a duplicate of [What does `(+)` do in a WHERE clause?](http://stackoverflow.com/questions/430274/oracle-what-does-do-in-a-where-clause) — Sylvain Leroux, May 22 '15 at 08:36
Please note, that this is deprecated (but still accepted) by Oracle since 9i R2. — Koshinae, May 22 '15 at 08:47

score 5 · Accepted Answer · answered May 22 '15 at 08:25

It's Oracle old outer join syntax:

To write a query that performs an outer join of tables A and B and returns all rows from A (a left outer join), use the LEFT [OUTER] JOIN syntax in the FROM clause, or apply the outer join operator (+) to all columns of B in the join condition in the WHERE clause. For all rows in A that have no matching rows in B, Oracle Database returns null for any select list expressions containing columns of B.

http://docs.oracle.com/cd/B19306_01/server.102/b14200/queries006.htm

What is (+) at the end of the query?

1 Answers1