DBIx::Class::ResultSource::View.3pm

Langue: en

Autres versions - même langue

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

Section: 3 (Bibliothèques de fonctions)

NAME

DBIx::Class::ResultSource::View - ResultSource object representing a view

SYNOPSIS

   package MyDB::Schema::Result::Year2000CDs;
 
   use base qw/DBIx::Class::Core/;
 
   __PACKAGE__->table_class('DBIx::Class::ResultSource::View');
 
   __PACKAGE__->table('year2000cds');
   __PACKAGE__->result_source_instance->is_virtual(1);
   __PACKAGE__->result_source_instance->view_definition(
       "SELECT cdid, artist, title FROM cd WHERE year ='2000'"
   );
   __PACKAGE__->add_columns(
     'cdid' => {
       data_type => 'integer',
       is_auto_increment => 1,
     },
     'artist' => {
       data_type => 'integer',
     },
     'title' => {
       data_type => 'varchar',
       size      => 100,
     },
   );
 
 

DESCRIPTION

View object that inherits from DBIx::Class::ResultSource

This class extends ResultSource to add basic view support.

A view has a ``view_definition'', which contains a SQL query. The query can only have parameters if ``is_virtual'' is set to true. It may contain JOINs, sub selects and any other SQL your database supports.

View definition SQL is deployed to your database on ``deploy'' in DBIx::Class::Schema unless you set ``is_virtual'' to true.

Deploying the view does not translate it between different database syntaxes, so be careful what you write in your view SQL.

Virtual views (``is_virtual'' true), are assumed to not exist in your database as a real view. The ``view_definition'' in this case replaces the view name in a FROM clause in a subselect.

EXAMPLES

Having created the MyDB::Schema::Year2000CDs schema as shown in the SYNOPSIS above, you can then:
   $2000_cds = $schema->resultset('Year2000CDs')
                      ->search()
                      ->all();
   $count    = $schema->resultset('Year2000CDs')
                      ->search()
                      ->count();
 
 

If you modified the schema to include a placeholder

   __PACKAGE__->result_source_instance->view_definition(
       "SELECT cdid, artist, title FROM cd WHERE year ='?'"
   );
 
 

and ensuring you have is_virtual set to true:

   __PACKAGE__->result_source_instance->is_virtual(1);
 
 

You could now say:

   $2001_cds = $schema->resultset('Year2000CDs')
                      ->search({}, { bind => [2001] })
                      ->all();
   $count    = $schema->resultset('Year2000CDs')
                      ->search({}, { bind => [2001] })
                      ->count();
 
 

SQL EXAMPLES

is_virtual set to false
   $schema->resultset('Year2000CDs')->all();
 
   SELECT cdid, artist, title FROM year2000cds me
 
 
is_virtual set to true
   $schema->resultset('Year2000CDs')->all();
 
   SELECT cdid, artist, title FROM 
     (SELECT cdid, artist, title FROM cd WHERE year ='2000') me
 
 

METHODS

is_virtual

   __PACKAGE__->result_source_instance->is_virtual(1);
 
 

Set to true for a virtual view, false or unset for a real database-based view.

view_definition

   __PACKAGE__->result_source_instance->view_definition(
       "SELECT cdid, artist, title FROM cd WHERE year ='2000'"
       );
 
 

An SQL query for your view. Will not be translated across database syntaxes.

OVERRIDDEN METHODS

from

Returns the FROM entry for the table (i.e. the view name) or the SQL as a subselect if this is a virtual view.

AUTHORS

Matt S. Trout <mst@shadowcatsystems.co.uk>

With Contributions from:

Guillermo Roditi <groditi@cpan.org>

Jess Robinson <castaway@desert-island.me.uk>

Wallace Reis <wreis@cpan.org>

LICENSE

You may distribute this code under the same terms as Perl itself.