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| admin | 9fc347d | 2006-09-21 00:00:28 +0000 | [diff] [blame] | 36 | <td><h1>Code Igniter User Guide Version 1.4.1</h1></td>
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| admin | b0dd10f | 2006-08-25 17:25:49 +0000 | [diff] [blame] | 37 | <td id="breadcrumb_right"><a href="../toc.html">Full Table of Contents</a></td>
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| 38 | </tr>
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| 42 |
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| 45 | <table cellpadding="0" cellspacing="0" border="0" style="width:100%">
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| 46 | <tr>
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| 47 | <td id="breadcrumb">
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| 48 | <a href="http://www.codeigniter.com/">Code Igniter Home</a> ›
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| 49 | <a href="../index.html">User Guide Home</a> ›
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| 50 | Models
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| 51 | </td>
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| 52 | <td id="searchbox"><form method="get" action="http://www.google.com/search"><input type="hidden" name="as_sitesearch" id="as_sitesearch" value="www.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>
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| 58 |
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| 59 |
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| 60 | <!-- START CONTENT -->
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| 61 | <div id="content">
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| 62 |
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| 63 | <h1>Models</h1>
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| 64 |
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| 65 | <p>Models are <strong>optionally</strong> available for those who want to use a more
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| 66 | traditional MVC approach.</p>
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| 67 |
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| 68 |
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| 69 |
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| 70 | <ul>
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| 71 | <li><a href="#what">What is a Model?</a></li>
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| 72 | <li><a href="#anatomy">Anatomy of a Model</a></li>
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| 73 | <li><a href="#loading">Loading a Model</a></li>
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| 74 | <li><a href="#conn">Connecting to your Database</a></li>
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| 75 |
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| 76 | </ul>
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| 77 |
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| 78 |
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| 79 | <a name="what"></a>
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| 80 | <h2>What is a Model?</h2>
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| 81 |
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| 82 | <p>Models are PHP classes that are designed to work with information in your database. For example, let's say
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| 83 | you use Code Igniter to manage a blog. You might have a model class that contains functions to insert, update, and
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| 84 | retrieve your blog data. Here is an example of what such a model class might look like:</p>
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| 85 |
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| 86 | <code>
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| 87 | class Blogmodel extends Model {<br />
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| 88 | <br />
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| 89 | var $title = '';<br />
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| 90 | var $content = '';<br />
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| 91 | var $date = '';<br />
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| 92 | <br />
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| 93 | function Blogmodel()<br />
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| 94 | {<br />
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| 95 | // Call the Model constructor<br />
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| 96 | parent::Model();<br />
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| 97 | }<br />
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| 98 | <br />
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| 99 | function get_last_ten_entries()<br />
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| 100 | {<br />
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| 101 | $query = $this->db->get('entries', 10);<br />
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| 102 | return $query->result();<br />
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| 103 | }<br />
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| 104 | <br />
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| 105 | function insert_entry()<br />
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| 106 | {<br />
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| 107 | $this->title = $_POST['title'];<br />
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| 108 | $this->content = $_POST['content'];<br />
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| 109 | $this->date = time();<br />
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| 110 | <br />
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| 111 | $this->db->insert('entries', $this);<br />
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| 112 | }<br />
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| 113 | <br />
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| 114 | function update_entry()<br />
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| 115 | {<br />
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| 116 | $this->title = $_POST['title'];<br />
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| 117 | $this->content = $_POST['content'];<br />
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| 118 | $this->date = time();<br />
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| 119 | <br />
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| 120 | $this->db->update('entries', $this, array('id', $_POST['id']));<br />
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| 121 | }<br />
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| 122 | <br />
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| 123 | }</code>
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| 124 |
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| 125 | <p>Note: The functions in the above example use the <a href="../libraries/database/active_record.html">Active Record</a> database functions.</p>
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| 126 |
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| 127 |
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| 128 | <a name="anatomy"></a>
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| 129 | <h2>Anatomy of a Model</h2>
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| 130 |
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| 131 | <p>Model classes are stored in your <dfn>application/models/</dfn> folder. The basic prototype for a model is this:</p>
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| 132 |
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| 133 |
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| 134 | <code>
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| 135 | class <var>Model_name</var> extends Model {<br />
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| 136 | <br />
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| 137 | function <var>Model_name</var>()<br />
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| 138 | {<br />
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| 139 | parent::Model();<br />
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| 140 | }<br />
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| 141 | }</code>
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| 142 |
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| 143 | <p>Where <var>Model_name</var> is the name of your class. Class names <strong>must</strong> be capitalized.
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| 144 | Make sure your class extends the base Model class.</p>
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| 145 |
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| 146 | <p>The file name will be a lower case version of your class name. For example, if your class is this:</p>
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| 147 |
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| 148 | <code>
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| 149 | class <var>User_model</var> extends Model {<br />
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| 150 | <br />
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| 151 | function <var>User_model</var>()<br />
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| 152 | {<br />
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| 153 | parent::Model();<br />
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| 154 | }<br />
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| 155 | }</code>
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| 156 |
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| 157 | <p>Your file will be this:</p>
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| 158 |
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| 159 | <code>application/models/<var>user_model.php</var></code>
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| 160 |
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| 161 |
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| 162 | <a name="loading"></a>
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| 163 | <h2>Loading a Model</h2>
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| 164 |
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| 165 | <p>Your models will typically be loaded and called from within your <a href="controllers.html">controller</a> functions.
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| 166 | To load a model you will use the following function:</p>
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| 167 |
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| 168 | <code>$this->load->model('<var>Model_name</var>');</code>
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| 169 |
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| 170 | <p>Once loaded, you will access your model functions using an object with the same name as your class:</p>
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| 171 |
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| 172 | <code>
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| 173 | $this->load->model('<var>Model_name</var>');<br />
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| 174 | <br />
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| 175 | $this-><var>Model_name</var>->function();
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| 176 | </code>
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| 177 |
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| 178 | <p>If you would like your model assigned to a different object name you can specify it via the second parameter of the loading
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| 179 | function:</p>
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| 180 |
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| 181 |
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| 182 | <code>
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| 183 | $this->load->model('<var>Model_name</var>', '<kbd>fubar</kbd>');<br />
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| 184 | <br />
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| 185 | $this-><kbd>fubar</kbd>->function();
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| 186 | </code>
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| 187 |
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| 188 | <p>Here is an example of a controller, that loads a model, then serves a view:</p>
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| 189 |
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| 190 | <code>
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| 191 | class Blog_controller extends Controller {<br />
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| 192 | <br />
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| 193 | function blog()<br />
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| 194 | {<br />
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| 195 | $this->load->model('Blog');<br />
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| 196 | <br />
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| 197 | $data['query'] = $this->Blog->get_last_ten_entries();<br /><br />
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| 198 | $this->load->view('blog', $data);<br />
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| 199 | }<br />
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| 200 | }</code>
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| 201 |
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| 202 |
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| 203 |
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| 204 | <a name="conn"></a>
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| 205 | <h2>Connecting to your Database</h2>
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| 206 |
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| 207 | <p>When a model is loaded it does <strong>NOT</strong> connect automatically to your database. The following options for connecting are available to you:</p>
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| 208 |
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| 209 | <ul>
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| 210 | <li>You can connect using the standard database methods <a href="../libraries/database/connecting.html">described here</a>, either from within your Controller class or your Model class.</li>
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| 211 | <li>You can tell the model loading function to auto-connect by passing <kbd>TRUE</kbd> (boolean) via the third parameter,
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| 212 | and connectivity settings, as defined in your database config file will be used:
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| 213 |
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| 214 | <code>$this->load->model('<var>Model_name</var>', '', <kbd>TRUE</kbd>);</code>
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| 215 | </li>
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| 216 |
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| 217 |
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| 218 | <li>You can manually pass database connectivity settings via the third parameter:
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| 219 |
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| 220 |
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| 221 | <code>$config['hostname'] = "localhost";<br />
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| 222 | $config['username'] = "myusername";<br />
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| 223 | $config['password'] = "mypassword";<br />
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| 224 | $config['database'] = "mydatabase";<br />
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| 225 | $config['dbdriver'] = "mysql";<br />
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| 226 | $config['dbprefix'] = "";<br />
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| 227 | $config['pconnect'] = FALSE;<br />
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| 228 | $config['db_debug'] = TRUE;<br />
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| 229 | $config['active_r'] = TRUE;<br />
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| 230 | <br />
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| 231 | $this->load->model('<var>Model_name</var>', '', <kbd>$config</kbd>);</code></li>
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| 232 | </ul>
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| 233 |
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| 234 |
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| 235 |
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| 236 |
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| 237 |
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| 238 |
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| 239 |
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| 240 | </div>
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| 241 | <!-- END CONTENT -->
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| 242 |
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| 243 |
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| 244 | <div id="footer">
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| 245 | <p>
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| 246 | Previous Topic: <a href="views.html">Views</a>
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| 247 | ·
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| 248 | <a href="#top">Top of Page</a> ·
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| 249 | <a href="../index.html">User Guide Home</a> ·
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| 250 | Next Topic: <a href="helpers.html">Helpers</a>
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| 251 | <p>
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| 252 | <p><a href="http://www.codeigniter.com">Code Igniter</a> · Copyright © 2006 · <a href="http://www.pmachine.com">pMachine, Inc.</a></p>
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| 253 | </div>
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