Страницы справочника OS X

Эта страница руководства для  версии 10.9 Mac OS X

Читать страницы руководства

DBIx::Class::ResultSource::View(3)   User Contributed Perl Documentation  DBIx::Class::ResultSource::View(3)



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

SYNOPSIS
         package MyApp::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 MyApp::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.

   deploy_depends_on
         __PACKAGE__->result_source_instance->deploy_depends_on(
             ["MyApp::Schema::Result::Year","MyApp::Schema::Result::CD"]
             );

       Specify the views (and only the views) that this view depends on.  Pass this an array reference of
       fully qualified result classes.

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.

OTHER METHODS
   new
       The constructor.

AUTHORS
       See "CONTRIBUTORS" in DBIx::Class.

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



perl v5.16.2                                     2012-08-16               DBIx::Class::ResultSource::View(3)