Question

I’m currently using CakePHP 2.0-RC1. Being pretty nifty and all, I’ve only come across one challenge that I can’t wrap my mind around. I’ve read the documentation on linking models together (http://www.cakedocs.com/models/associations-linking-models-together.html), but how to I tell CakePHP to search trough a relation table and find the values I’m after? Let me explain.

I have a database structure similar to the following (it has been simplified for the question. PK = Primary Key. FK = Foreign Key )

game

 - INT(11) id (PK)
 - VARCHAR(100) name
 - VARCHAR(40) year
 - VARCHAR(10) age

category

 - INT(11) id (PK)
 - VARCHAR(50) name

game_category

 - INT(11) game_id (FK)
 - INT(11) category_id (FK)

Explanation to the relationship between these:

A game can have one or more category. This relation is defined in “game_category” table. I want CakePHP to not only find what category id a game has, I want the category name as well when I do $this->Game->find(‘first’) for instance. I would guess CakePHP needs to be told to “continue through the game_category table and onto the category table” and find what the name of each category actually is.

I have these Models

Game.php

<?php
class Game extends AppModel {
    var $useTable = 'game';

    var $hasMany = array(
    'GameCategory' => array(
        'fields' => '*',
        'className' => 'GameCategory',
        )
    );

    var $hasOne = 'Review';  
}
?>

GameCategory.php

<?php
class GameCategory extends AppModel {
    var $useTable = 'game_category';

    var $belongsTo = 'category';

    var $hasMany = array(
    'Category' => array(
        'fields' => '*',
        'foreignKey' => 'category_id',
        'className' => 'Category',
        'conditions' => array('GameCategory.game_id' => 'Game.id', 'GameCategory.category_id' => 'Category.id'),
    )
    );
}
?>

Category.php

<?php
class Category extends AppModel {
    var $useTable = 'category';   
    var $belongsTo = 'GameCategory';
}
?>

By the relations defined above, I get results like this:

Array
(
    [Game] => Array
        (
            [id] => 2
            [name] => Colonization
            [year] => 1995
            [age] => 7
        )

    [GameCategory] => Array
        (
            [0] => Array
                (
                    [game_id] => 2
                    [category_id] => 19
                )

            [1] => Array
                (
                    [game_id] => 2
                    [category_id] => 16
                )

        )
)

The only thing remaining is just getting the actual name of each category. I hope some of this made any sense.

Any help is appreciated.

Answer 1

You should see hasAndBelongsToMany (HABTM) in book online and should change table name game_category to games_categories for correct conventions.

Game.php

<?php
class Game extends AppModel {
    var $name = 'Game';
    var $hasAndBelongsToMany = array(
    'Category' =>
        array(
            'className'              => 'Category',
            'joinTable'              => 'game_category',
            'foreignKey'             => 'game_id',
            'associationForeignKey'  => 'category_id',
        )
);

}
?>