What does the symbol (+) mean at the end of a WHERE statement? I have never seen it at the end of a statement and it is causing me much confusion. Does anyone have an idea?
Example: Where(table1.number = table2.number (+))
Asked
Active
Viewed 600 times
1
Jonathan Leffler
- 730,956
- 141
- 904
- 1,278
Arturo Delgado
- 23
- 2
-
1What DBMS are you using? Have you read the documentation of its SQL syntax? – Barmar Jul 03 '13 at 23:23
-
2It is old Oracle syntax. – Lion Jul 03 '13 at 23:26
1 Answers
3
It could be use to do joins, but its not recommended:
Afaik, the + notation is only present for backwards compatibility because Oracle debuted it before the ANSI standard for joins was put in place. It's specific to Oracle and you should avoid using it in new code when there's an equivalent standards-compliant version available.
Edit: It seems there are differences between the two, and the + notation has restrictions that the ANSI join syntax does not have. Oracle themselves recommend that you not use the + notation.
From here: Difference between Oracle's plus (+) notation and ansi JOIN notation?
In Oracle, (+) denotes the "optional" table in the JOIN.
From here: Left Outer Join using + sign in Oracle 11g
