| <!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> | |
| <title>CodeIgniter User Guide : Field Data</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="Content-Type" content="text/html; charset=utf-8" /> | |
| <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.jpg" width="153" height="44" 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 1.6.0</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> › | |
| <a href="index.html">Database Library</a> › | |
| Field Names | |
| </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>Field Data</h1> | |
| <h2>$this->db->list_fields()</h2> | |
| <p>Returns an array containing the field names. This query can be called two ways:</p> | |
| <p>1. You can supply the table name and call it from the <dfn>$this->db-></dfn> object:</p> | |
| <code> | |
| $fields = $this->db->list_fields('table_name')<br /><br /> | |
| foreach ($fields as $field)<br /> | |
| {<br /> | |
| echo $field;<br /> | |
| } | |
| </code> | |
| <p>2. You can gather the field names associated with any query you run by calling the function | |
| from your query result object:</p> | |
| <code> | |
| $query = $this->db->query('SELECT * FROM some_table') | |
| <br /><br /> | |
| foreach ($query->list_fields() as $field)<br /> | |
| {<br /> | |
| echo $field;<br /> | |
| } | |
| </code> | |
| <h2>$this->db->field_exists()</h2> | |
| <p>Sometimes it's helpful to know whether a particular field exists before performing an action. | |
| Returns a boolean TRUE/FALSE. Usage example:</p> | |
| <code> | |
| if ($this->db->field_exists('field_name', 'table_name'))<br /> | |
| {<br /> | |
| // some code...<br /> | |
| } | |
| </code> | |
| <p>Note: Replace <em>field_name</em> with the name of the column you are looking for, and replace | |
| <em>table_name</em> with the name of the table you are looking for.</p> | |
| <h2>$this->db->field_data()</h2> | |
| <p>Returns an array of objects containing field information.</p> | |
| <p>Sometimes it's helpful to gather the field names or other metadata, like the column type, max length, etc.</p> | |
| <p class="important">Note: Not all databases provide meta-data.</p> | |
| <p>Usage example:</p> | |
| <code> | |
| $fields = $this->db->field_data('table_name')<br /><br /> | |
| foreach ($fields as $field)<br /> | |
| {<br /> | |
| echo $field->name;<br /> | |
| echo $field->type;<br /> | |
| echo $field->max_length;<br /> | |
| echo $field->primary_key;<br /> | |
| } | |
| </code> | |
| <p>If you have run a query already you can use the result object instead of supplying the table name:</p> | |
| <code> | |
| $query = $this->db->query("YOUR QUERY")<br /> | |
| $fields = $query->field_data() | |
| </code> | |
| <p>The following data is available from this function if supported by your database:</p> | |
| <ul> | |
| <li>name - column name</li> | |
| <li>max_length - maximum length of the column</li> | |
| <li>primary_key - 1 if the column is a primary key</li> | |
| <li>type - the type of the column</li> | |
| </ul> | |
| </div> | |
| <!-- END CONTENT --> | |
| <div id="footer"> | |
| <p> | |
| Previous Topic: <a href="table_data.html"> Table Data</a> | |
| · | |
| <a href="#top">Top of Page</a> · | |
| <a href="../index.html">User Guide Home</a> · | |
| Next Topic: <a href="call_function.html">Custom Function Calls</a> | |
| </p> | |
| <p><a href="http://codeigniter.com">CodeIgniter</a> · Copyright © 2007 · <a href="http://ellislab.com/">Ellislab, Inc.</a></p> | |
| </div> | |
| </body> | |
| </html> |