DBIx::Class::SQLAHacks::OracleJoins.3pm

Langue: en

Autres versions - même langue

Version: 2010-06-04 (ubuntu - 24/10/10)

Section: 3 (Bibliothèques de fonctions)

NAME

DBIx::Class::SQLAHacks::OracleJoins - Pre-ANSI Joins-via-Where-Clause Syntax

PURPOSE

This module was originally written to support Oracle < 9i where ANSI joins weren't supported at all, but became the module for Oracle >= 8 because Oracle's optimising of ANSI joins is horrible.

SYNOPSIS

Not intended for use directly; used as the sql_maker_class for schemas and components.

DESCRIPTION

Implements pre-ANSI joins specified in the where clause. Instead of:
     SELECT x FROM y JOIN z ON y.id = z.id
 
 

It will write:

     SELECT x FROM y, z WHERE y.id = z.id
 
 

It should properly support left joins, and right joins. Full outer joins are not possible due to the fact that Oracle requires the entire query be written to union the results of a left and right join, and by the time this module is called to create the where query and table definition part of the sql query, it's already too late.

METHODS

select ($\@$;$$@)
Replaces DBIx::Class::SQLAHacks's select() method, which calls _oracle_joins() to modify the column and table list before calling SUPER::select().
_recurse_from ($$\@)
Recursive subroutine that builds the table list.
_oracle_joins ($$$@)
Creates the left/right relationship in the where query.

BUGS

Does not support full outer joins. Probably lots more.

SEE ALSO

DBIx::Class::Storage::DBI::Oracle::WhereJoins - Storage class using this
DBIx::Class::SQLAHacks - Parent module
DBIx::Class - Duh

AUTHOR

Justin Wheeler "<jwheeler@datademons.com>"

CONTRIBUTORS

David Jack Olrik "<djo@cpan.org>"

LICENSE

This module is licensed under the same terms as Perl itself.