Tree::Persist::DB::SelfReferential - a handler for Tree persistence

Please see Tree::Persist for how to use this module.

This module is a plugin for Tree::Persist to store a Tree to a self-referential DB table. This is where a table contains an id column for the row and a parent_id column that refers back to another row's id (which is the parent row).

This is the simplest way to store a tree datastructure in a database, but it has performance penalties.

In addition to any parameters required by its parent Tree::Persist::DB, the following parameters are required by connect():

* id (required)

This is the id for the root node of the tree. By specifying this, you can both store more that one tree in a table as well as only load a subtree.

* id_col (optional)

This is the column name for the id field. It defaults to "id".

* parent_id_col (optional)

This is the column name for the parent_id field. It defaults to "parent_id".

* value_col (optional)

This is the column name for the value field. It defaults to "value".

* class_col (optional)

This is the column name for the class field. If unset, the class parameter will be used.

• To date, only MySQL has been tested.
• Provide for a way to default the class to 'Tree' if no class_col is provided. Also, allow for the classname to be passed into the constructor.

Please see the relevant section of Tree::Persist.

Please see the relevant section of Tree::Persist.

Rob Kinyon <rob.kinyon@iinteractive.com>

Stevan Little <stevan.little@iinteractive.com>

Thanks to Infinity Interactive for generously donating our time.

Copyright 2004, 2005 by Infinity Interactive, Inc.

http://www.iinteractive.com

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.