NAME

DBIx::Class::Storage::DBI::Oracle::WhereJoins - Oracle joins in WHERE syntax support (instead of ANSI).

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. (See: http://scsys.co.uk:8001/7495)

SYNOPSIS

DBIx::Class should automagically detect Oracle and use this module with no work from you.

DESCRIPTION

This class implements Oracle's WhereJoin support. 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

This module replaces a subroutine contained in DBIC::SQL::Abstract:

sql_maker

It also creates a new module in its BEGIN { } block called DBIC::SQL::Abstract::Oracle which has the following methods:

select ($\@$;$$@)

Replaces DBIC::SQL::Abstract'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

DBIC::SQL::Abstract

DBIx::Class::Storage::DBI::Oracle::Generic

DBIx::Class

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.