<!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>Field Data : 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 2.0.3</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 © 2006 - 2011 · <a href="http://ellislab.com/">EllisLab, Inc.</a></p> </div> </body> </html>