Welcome to the Cookbook

A Model represents your data model. In object-oriented programming a data model is an object that represents a "thing", like a car, a person, or a house. A blog, for example, may have many blog posts and each blog post may have many comments. The Blog, Post, and Comment are all examples of models, each associated with another.

Here is a simple example of a model definition in CakePHP:

<?php

class Ingredient extends AppModel {
    var $name = 'Ingredient';
}

?>

1. <?php
2. class Ingredient extends AppModel {
3. var $name = 'Ingredient';
4. }
5. ?>

With just this simple declaration, the Ingredient model is bestowed with all the functionality you need to create queries along with saving and deleting data. These magic methods come from CakePHP's Model class by the magic of inheritance. The Ingredient model extends the application model, AppModel, which extends CakePHP's internal Model class. It is this core Model class that bestows the functionality onto your Ingredient model.

This intermediate class, AppModel, is empty and if you haven't created your own is taken from within the /cake/ folder. Overriding the AppModel allows you to define functionality that should be made available to all models within your application. To do so, you need to create your own app_model.php file that resides in the root of the /app/ folder. Creating a project using Bake will automatically generate this file for you.

Create your model PHP file in the /app/models/ directory or in a subdirectory of /app/models. CakePHP will find it anywhere in the directory. By convention it should have the same name as the class; for this example ingredient.php.

CakePHP will dynamically create a model object for you if it cannot find a corresponding file in /app/models. This also means that if your model file isn't named correctly (i.e. Ingredient.php or ingredients.php) CakePHP will use a instance of AppModel rather than your missing (from CakePHP's perspective) model file. If you're trying to use a method you've defined in your model, or a behavior attached to your model and you're getting SQL errors that are the name of the method you're calling - it's a sure sign CakePHP can't find your model and you either need to check the file names, clear your tmp files, or both.

See also Behaviors for more information on how to apply similar logic to multiple models.

The $name property is necessary for PHP4 but optional for PHP5.

With your model defined, it can be accessed from within your Controller. CakePHP will automatically make the model available for access when its name matches that of the controller. For example, a controller named IngredientsController will automatically initialize the Ingredient model and attach it to the controller at $this->Ingredient.

<?php
class IngredientsController extends AppController {
    function index() {
        //grab all ingredients and pass it to the view:
        $ingredients = $this->Ingredient->find('all');
        $this->set('ingredients', $ingredients);
    }
}

?>

1. <?php
2. class IngredientsController extends AppController {
3. function index() {
4. //grab all ingredients and pass it to the view:
5. $ingredients = $this->Ingredient->find('all');
6. $this->set('ingredients', $ingredients);
7. }
8. }
9. ?>

Associated models are available through the main model. In the following example, Recipe has an association with the Ingredient model.

<?php
class RecipesController extends AppController {
    function index() {
        $ingredients = $this->Recipe->Ingredient->find('all');
        $this->set('ingredients', $ingredients);
    }
}
?>

1. <?php
2. class RecipesController extends AppController {
3. function index() {
4. $ingredients = $this->Recipe->Ingredient->find('all');
5. $this->set('ingredients', $ingredients);
6. }
7. }
8. ?>

If models have absolutely NO association between them, you can use Controller::loadModel() to get the model.

<?php
class RecipesController extends AppController {
    function index() {
       $recipes = $this->Recipe->find('all');
       
       $this->loadModel('Car');
       $cars = $this->Car->find('all');
       
       $this->set(compact('recipes', 'cars'));
    }
}
?>

1. <?php
2. class RecipesController extends AppController {
3. function index() {
4. $recipes = $this->Recipe->find('all');
6. $this->loadModel('Car');
7. $cars = $this->Car->find('all');
9. $this->set(compact('recipes', 'cars'));
10. }
11. }
12. ?>

Some class names are not usable for model names. For instance "File" cannot be used as "File" is a class already existing in the CakePHP core.