ANSI join syntax
The following ANSI joins are supported:
- Left outer join
- Right outer join
The ANSI outer-join syntax begins an outer join with the LEFT JOIN, LEFT OUTER JOIN, RIGHT JOIN, or RIGHT OUTER JOIN keywords. The OUTER keyword is optional. Queries can specify a join condition and optional join filters in the ON clause. The WHERE clause specifies a post-join filter. In addition, you can explicitly specify the type of join using the LEFT or right clause. ANSI join syntax also allows the dominant or subordinate part of an outer join to be the result set of another join, when you begin the join with a left parenthesis.
If
you use ANSI syntax for an outer join, you must use the ANSI syntax
for all outer joins in a single query block.
Tip: The examples in this section use table
aliases for brevity. Aliases discusses
table aliases.