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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><title>Models : CodeIgniter User Guide</title><style type='text/css' media='all'>@import url('../userguide.css');</style><link rel='stylesheet' type='text/css' media='all' href='../userguide.css' /><script type="text/javascript" src="../nav/nav.js"></script><script type="text/javascript" src="../nav/prototype.lite.js"></script><script type="text/javascript" src="../nav/moo.fx.js"></script><script type="text/javascript" src="../nav/user_guide_menu.js"></script><meta http-equiv='expires' content='-1' /><meta http-equiv= 'pragma' content='no-cache' /><meta name='robots' content='all' /><meta name='author' content='ExpressionEngine Dev Team' /><meta name='description' content='CodeIgniter User Guide' /></head><body><!-- START NAVIGATION --><div id="nav"><div id="nav_inner"><script type="text/javascript">create_menu('../');</script></div></div><div id="nav2"><a name="top"></a><a href="javascript:void(0);" onclick="myHeight.toggle();"><img src="../images/nav_toggle_darker.jpg" width="154" height="43" border="0" title="Toggle Table of Contents" alt="Toggle Table of Contents" /></a></div><div id="masthead"><table cellpadding="0" cellspacing="0" border="0" style="width:100%"><tr><td><h1>CodeIgniter User Guide Version 1.7.1</h1></td><td id="breadcrumb_right"><a href="../toc.html">Table of Contents Page</a></td></tr></table></div><!-- END NAVIGATION --><!-- START BREADCRUMB --><table cellpadding="0" cellspacing="0" border="0" style="width:100%"><tr><td id="breadcrumb"><a href="http://codeigniter.com/">CodeIgniter Home</a> › <a href="../index.html">User Guide Home</a> › Models</td><td id="searchbox"><form method="get" action="http://www.google.com/search"><input type="hidden" name="as_sitesearch" id="as_sitesearch" value="codeigniter.com/user_guide/" />Search User Guide <input type="text" class="input" style="width:200px;" name="q" id="q" size="31" maxlength="255" value="" /> <input type="submit" class="submit" name="sa" value="Go" /></form></td></tr></table><!-- END BREADCRUMB --><br clear="all" /><!-- START CONTENT --><div id="content"><h1>Models</h1><p>Models are <strong>optionally</strong> available for those who want to use a more traditional MVC approach.</p><ul><li><a href="#what">What is a Model?</a></li><li><a href="#anatomy">Anatomy of a Model</a></li><li><a href="#loading">Loading a Model</a></li><li><a href="#auto_load_model">Auto-Loading a Model</a> </li><li><a href="#conn">Connecting to your Database</a></li></ul><h2><a name="what"></a>What is a Model?</h2><p>Models are PHP classes that are designed to work with information in your database. For example, let's sayyou use CodeIgniter to manage a blog. You might have a model class that contains functions to insert, update, andretrieve your blog data. Here is an example of what such a model class might look like:</p><code>class Blogmodel extends Model {<br /><br /> var $title = '';<br /> var $content = '';<br /> var $date = '';<br /><br /> function Blogmodel()<br /> {<br /> // Call the Model constructor<br /> parent::Model();<br /> }<br /> <br /> function get_last_ten_entries()<br /> {<br /> $query = $this->db->get('entries', 10);<br /> return $query->result();<br /> }<br /><br /> function insert_entry()<br /> {<br /> $this->title = $_POST['title']; // please read the below note<br /> $this->content = $_POST['content'];<br /> $this->date = time();<br /><br /> $this->db->insert('entries', $this);<br /> }<br /><br /> function update_entry()<br /> {<br /> $this->title = $_POST['title'];<br /> $this->content = $_POST['content'];<br /> $this->date = time();<br /><br /> $this->db->update('entries', $this, array('id' => $_POST['id']));<br /> }<br /><br />}</code><p>Note: The functions in the above example use the <a href="../database/active_record.html">Active Record</a> database functions.</p><p class="important"><strong>Note:</strong> For the sake of simplicity in this example we're using $_POST directly. This is generally bad practice, and a more common approach would be to use the <a href="../libraries/input.html">Input Class</a> $this->input->post('title')</p><h2><a name="anatomy"></a>Anatomy of a Model</h2><p>Model classes are stored in your <dfn>application/models/</dfn> folder. They can be nested within sub-folders if youwant this type of organization.</p><p>The basic prototype for a model class is this:</p><code>class <var>Model_name</var> extends Model {<br /><br /> function <var>Model_name</var>()<br /> {<br /> parent::Model();<br /> }<br />}</code><p>Where <var>Model_name</var> is the name of your class. Class names <strong>must</strong> have the first letter capitalized with the rest of the name lowercase.Make sure your class extends the base Model class.</p><p>The file name will be a lower case version of your class name. For example, if your class is this:</p><code>class <var>User_model</var> extends Model {<br /><br /> function <var>User_model</var>()<br /> {<br /> parent::Model();<br /> }<br />}</code><p>Your file will be this:</p><code>application/models/<var>user_model.php</var></code><h2><a name="loading"></a>Loading a Model</h2><p>Your models will typically be loaded and called from within your <a href="controllers.html">controller</a> functions.To load a model you will use the following function:</p><code>$this->load->model('<var>Model_name</var>');</code><p>If you model is located in a sub-folder, include the relative path from your models folder. For example, ifyou have a model located at <dfn>application/models/blog/queries.php</dfn> you'll load it using:</p><code>$this->load->model('<var>blog/queries</var>');</code><p>Once loaded, you will access your model functions using an object with the same name as your class:</p><code>$this->load->model('<var>Model_name</var>');<br /><br />$this-><var>Model_name</var>->function();</code><p>If you would like your model assigned to a different object name you can specify it via the second parameter of the loadingfunction:</p><code>$this->load->model('<var>Model_name</var>', '<kbd>fubar</kbd>');<br /><br />$this-><kbd>fubar</kbd>->function();</code><p>Here is an example of a controller, that loads a model, then serves a view:</p><code>class Blog_controller extends Controller {<br /><br /> function blog()<br /> {<br /> $this->load->model('Blog');<br /><br /> $data['query'] = $this->Blog->get_last_ten_entries();<br /><br /> $this->load->view('blog', $data);<br /> }<br />}</code><h2><a name="auto_load_model" id="auto_load_model"></a>Auto-loading Models</h2><p>If you find that you need a particular model globally throughout your application, you can tell CodeIgniter to auto-load it during system initialization. This is done by opening the application/config/autoload.php file and adding the model to the autoload array.</p><h2><a name="conn"></a>Connecting to your Database</h2><p>When a model is loaded it does <strong>NOT</strong> connect automatically to your database. The following options for connecting are available to you:</p><ul><li>You can connect using the standard database methods <a href="../database/connecting.html">described here</a>, either from within your Controller class or your Model class.</li><li>You can tell the model loading function to auto-connect by passing <kbd>TRUE</kbd> (boolean) via the third parameter,and connectivity settings, as defined in your database config file will be used:<code>$this->load->model('<var>Model_name</var>', '', <kbd>TRUE</kbd>);</code></li><li>You can manually pass database connectivity settings via the third parameter:<code>$config['hostname'] = "localhost";<br />$config['username'] = "myusername";<br />$config['password'] = "mypassword";<br />$config['database'] = "mydatabase";<br />$config['dbdriver'] = "mysql";<br />$config['dbprefix'] = "";<br />$config['pconnect'] = FALSE;<br />$config['db_debug'] = TRUE;<br /><br />$this->load->model('<var>Model_name</var>', '', <kbd>$config</kbd>);</code></li></ul></div><!-- END CONTENT --><div id="footer"><p>Previous Topic: <a href="views.html">Views</a> · <a href="#top">Top of Page</a> · <a href="../index.html">User Guide Home</a> · Next Topic: <a href="helpers.html">Helpers</a></p><p><a href="http://codeigniter.com">CodeIgniter</a> · Copyright © 2006-2008 · <a href="http://ellislab.com/">Ellislab, Inc.</a></p></div></body></html>