NAME¶

Rose::DB::Object::Metadata::Relationship::OneToMany - One to many table relationship metadata object.

SYNOPSIS¶

  use Rose::DB::Object::Metadata::Relationship::OneToMany;
  $rel = Rose::DB::Object::Metadata::Relationship::OneToMany->new(...);
  $rel->make_methods(...);
  ...

DESCRIPTION¶

Objects of this class store and manipulate metadata for relationships in which a single row from one table refers to multiple rows in another table. This class inherits from Rose::DB::Object::Metadata::Relationship. Inherited methods that are not overridden will not be documented a second time here. See the Rose::DB::Object::Metadata::Relationship documentation for more information.

METHOD MAP¶

"count"

Rose::DB::Object::MakeMethods::Generic, objects_by_key, "interface => 'count'" ...

"find"

Rose::DB::Object::MakeMethods::Generic, objects_by_key, "interface => 'find'" ...

"iterator"

Rose::DB::Object::MakeMethods::Generic, objects_by_key, "interface => 'iterator'" ...

"get_set"

Rose::DB::Object::MakeMethods::Generic, objects_by_key, "interface => 'get_set'" ...

"get_set_now"

Rose::DB::Object::MakeMethods::Generic, objects_by_key, "interface => 'get_set_now'" ...

"get_set_on_save"

Rose::DB::Object::MakeMethods::Generic, objects_by_key, "interface => 'get_set_on_save'" ...

"add_now"

Rose::DB::Object::MakeMethods::Generic, objects_by_key, "interface => 'add_now'" ...

"add_on_save"

Rose::DB::Object::MakeMethods::Generic, objects_by_key, "interface => 'add_on_save'" ...

See the Rose::DB::Object::Metadata::Relationship documentation for an explanation of this method map.

CLASS METHODS¶

default_auto_method_types [TYPES]

Get or set the default list of auto_method_types. TYPES should be a list of relationship method types. Returns the list of default relationship method types (in list context) or a reference to an array of the default relationship method types (in scalar context). The default list contains "find", "get_set_on_save", and "add_on_save".

OBJECT METHODS¶

build_method_name_for_type TYPE

Return a method name for the relationship method type TYPE.

 

For the method types "get_set", "get_set_now", and "get_set_on_save", the relationship's name is returned.

 

For the method types "add_now" and "add_on_save", the relationship's name prefixed with "add_" is returned.

 

For the method type "find", the relationship's name prefixed with "find_" is returned.

 

For the method type "count", the relationship's name suffixed with "_count" is returned.

 

For the method type "iterator", the relationship's name suffixed with "_iterator" is returned.

 

Otherwise, undef is returned.

is_singular

Returns false.

manager_class [CLASS]

Get or set the name of the Rose::DB::Object::Manager-derived class used to fetch objects. The make_methods method will use Rose::DB::Object::Manager if this value is left undefined.

 

Note: when the name of a relationship that has "manager_args" is used in a Rose::DB::Object::Manager with_objects or require_objects parameter value, only the sort_by argument will be copied from "manager_args" and incorporated into the query.

manager_method [METHOD]

Get or set the name of the manager_class class method to call when fetching objects. The make_methods method will use get_objects if this value is left undefined.

manager_count_method [METHOD]

Get or set the name of the manager_class class method to call when counting objects. The make_methods method will use get_objects_count if this value is left undefined.

manager_iterator_method [METHOD]

Get or set the name of the manager_class class method to call when creating an iterator. The make_methods method will use get_objects_iterator if this value is left undefined.

manager_args [HASHREF]

Get or set a reference to a hash of name/value arguments to pass to the manager_method when fetching objects. For example, this can be used to enforce a particular sort order for objects fetched via this relationship. For example:

 

  Product->meta->add_relationship
  (
    code_names =>
    {
      type         => 'one to many',
      class        => 'CodeName',
      column_map   => { id => 'product_id' },
      manager_args => 
      {
        sort_by => CodeName->meta->table . '.name',
      },
    },
  );
    

 

This would ensure that a "Product"'s "code_names()" are listed in alphabetical order. Note that the "name" column is prefixed by the name of the table fronted by the "CodeName" class. This is important because several tables may have a column named "name." If this relationship is used to form a JOIN in a query along with one of those tables, then the "name" column will be ambiguous. Adding a table name prefix disambiguates the column name.

 

Also note that the table name is not hard-coded. Instead, it is fetched from the Rose::DB::Object-derived class that fronts the table. This is more verbose, but is a much better choice than including the literal table name when it comes to long-term maintenance of the code.

 

See the documentation for Rose::DB::Object::Manager's get_objects method for a full list of valid arguments for use with the "manager_args" parameter, but remember that you can define your own custom manager_class and thus can also define what kinds of arguments "manager_args" will accept.

map_column LOCAL [, FOREIGN]

If passed a local column name LOCAL, return the corresponding column name in the foreign table. If passed both a local column name LOCAL and a foreign column name FOREIGN, set the local/foreign mapping and return the foreign column name.

column_map [HASH | HASHREF]

Get or set a reference to a hash that maps local column names to foreign column names.

query_args [ARRAYREF]

Get or set a reference to an array of query arguments to add to the query passed to the manager_method when fetching objects.

type

Returns "one to many".

AUTHOR¶

John C. Siracusa (siracusa@gmail.com)

LICENSE¶

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.