DOKK / manpages / debian 12 / librose-db-object-perl / Rose::DB::Object::Std::Metadata.3pm.en
Rose::DB::Object::Std::Metadata(3pm) User Contributed Perl Documentation Rose::DB::Object::Std::Metadata(3pm)

Rose::DB::Object::Std::Metadata - Standardized database object metadata.

  use Rose::DB::Object::Std::Metadata;
  $meta = Rose::DB::Object::Std::Metadata->new(class => 'Product');
  # ...or...
  # $meta = Rose::DB::Object::Std::Metadata->for_class('Product');
  $meta->table('products');
  $meta->columns
  (
    id          => { type => 'int', primary_key => 1 },
    name        => { type => 'varchar', length => 255 },
    description => { type => 'text' },
    category_id => { type => 'int' },
    status => 
    {
      type      => 'varchar', 
      check_in  => [ 'active', 'inactive' ],
      default   => 'inactive',
    },
    start_date  => { type => 'datetime' },
    end_date    => { type => 'datetime' },
    date_created     => { type => 'timestamp', default => 'now' },  
    last_modified    => { type => 'timestamp', default => 'now' },
  );
  $meta->add_unique_key('name');
  $meta->foreign_keys
  (
    category =>
    {
      class       => 'Category',
      key_columns =>
      {
        category_id => 'id',
      }
    },
  );
  ...

"Rose::DB::Object::Std::Metadata" is a subclass of Rose::DB::Object::Metadata that is designed to serve the needs of Rose::DB::Object::Std objects. See the Rose::DB::Object::Std documentations for information on what differentiates it from Rose::DB::Object.

Only the methods that are overridden are documented here. See the Rose::DB::Object::Metadata documentation for the rest.

This method is an alias for the "add_primary_key_columns()" method.
Since Rose::DB::Object::Std objects must have a single primary key column named "id", calling this method with a COLUMNS argument of anything other than the column name "id" or a reference to an array containing the column name "id" will cause a fatal error.

In general, you do not need to use this method at all since the "primary_key_columns()" method is hard-coded to always return "id".

This method does the same thing as the Rose::DB::Object::Metadata method of the same name, with one exception. If there is no column named "id" in the list of columns, a scalar primary key column named "id" is added to the column list. Then initialization proceeds as usual.
Always returns the column name "id" (in list context) or a reference to an array containing the column name "id" (in scalar context).

John C. Siracusa (siracusa@gmail.com)

Copyright (c) 2010 by John C. Siracusa. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

2022-10-14 perl v5.34.0