Gitiles
Code Review Sign In
www.giggi.me / code-igniter-v3-giggi / 257651d498cbd8c998520b12a1001524cfb88d69 / . / user_guide / database / fields.html
blob: d6f273ede59d7b6b9c92c0f468b6be5c350a60af [file] [log] [blame]
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]1<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
2<html>
3<head>
4
5<title>Code Igniter User Guide</title>
6
7<style type='text/css' media='all'>@import url('../userguide.css');</style>
8<link rel='stylesheet' type='text/css' media='all' href='../userguide.css' />
9
admin17a890d2006-09-27 20:42:42 +0000[diff] [blame]10<script type="text/javascript" src="../nav/nav.js"></script>
admin2296fc32006-09-27 21:07:02 +0000[diff] [blame]11<script type="text/javascript" src="../nav/prototype.lite.js"></script>
admin17a890d2006-09-27 20:42:42 +0000[diff] [blame]12<script type="text/javascript" src="../nav/moo.fx.js"></script>
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]13<script type="text/javascript">
14window.onload = function() {
admine334c472006-10-21 19:44:22 +0000[diff] [blame]15 myHeight = new fx.Height('nav', {duration: 400});
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]16 myHeight.hide();
17}
18</script>
19
20<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
21<meta http-equiv='expires' content='-1' />
22<meta http-equiv= 'pragma' content='no-cache' />
23<meta name='robots' content='all' />
24<meta name='author' content='Rick Ellis' />
25<meta name='description' content='Code Igniter User Guide' />
26
27</head>
28<body>
29
30<!-- START NAVIGATION -->
31<div id="nav"><div id="nav_inner"><script type="text/javascript">create_menu('../');</script></div></div>
32<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>
33<div id="masthead">
34<table cellpadding="0" cellspacing="0" border="0" style="width:100%">
35<tr>
Rick Ellis257651d2006-11-23 18:40:13 +0000[diff] [blame^]36<td><h1>Code Igniter User Guide Version 1.5.1</h1></td>
adminc0d5d522006-10-30 19:40:35 +0000[diff] [blame]37<td id="breadcrumb_right"><a href="../toc.html">Table of Contents Page</a></td>
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]38</tr>
39</table>
40</div>
41<!-- END NAVIGATION -->
42
43<!-- START BREADCRUMB -->
44<table cellpadding="0" cellspacing="0" border="0" style="width:100%">
45<tr>
46<td id="breadcrumb">
47<a href="http://www.codeigniter.com/">Code Igniter Home</a> &nbsp;&#8250;&nbsp;
48<a href="../index.html">User Guide Home</a> &nbsp;&#8250;&nbsp;
49<a href="index.html">Database Library</a> &nbsp;&#8250;&nbsp;
50Field Names
51</td>
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&nbsp; <input type="text" class="input" style="width:200px;" name="q" id="q" size="31" maxlength="255" value="" />&nbsp;<input type="submit" class="submit" name="sa" value="Go" /></form></td>
53</tr>
54</table>
55<!-- END BREADCRUMB -->
56
57
58<br clear="all" />
59
60
61<!-- START CONTENT -->
62<div id="content">
63
64
65<h1>Field Data</h1>
66
67
admin194b8942006-10-04 07:59:32 +0000[diff] [blame]68<h2>$this->db->list_fields()</h2>
adminab4f61b2006-09-25 22:12:32 +0000[diff] [blame]69<p>Returns an array containing the field names. This query can be called two ways:</p>
70
71
72<p>1. You can supply the table name and call it from the <dfn>$this->db-></dfn> object:</p>
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]73
74<code>
admin194b8942006-10-04 07:59:32 +0000[diff] [blame]75$fields = $this->db->list_fields('table_name')<br /><br />
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]76
77foreach ($fields as $field)<br />
78{<br />
79&nbsp;&nbsp;&nbsp;echo $field;<br />
80}
81</code>
82
admine334c472006-10-21 19:44:22 +0000[diff] [blame]83<p>2. You can gather the field names associated with any query you run by calling the function
adminab4f61b2006-09-25 22:12:32 +0000[diff] [blame]84from your query result object:</p>
85
86<code>
admin194b8942006-10-04 07:59:32 +0000[diff] [blame]87$query = $this->db->query('SELECT * FROM some_table')
adminab4f61b2006-09-25 22:12:32 +0000[diff] [blame]88<br /><br />
89
admin3dd978f2006-09-30 19:24:45 +0000[diff] [blame]90foreach ($query->list_fields() as $field)<br />
adminab4f61b2006-09-25 22:12:32 +0000[diff] [blame]91{<br />
92&nbsp;&nbsp;&nbsp;echo $field;<br />
93}
94</code>
95
96
admin194b8942006-10-04 07:59:32 +0000[diff] [blame]97<h2>$this->db->field_exists()</h2>
adminb2a9cec2006-10-01 03:38:04 +0000[diff] [blame]98
admine7e1dcd2006-10-21 18:04:01 +0000[diff] [blame]99<p>Sometimes it's helpful to know whether a particular field exists before performing an action.
adminb2a9cec2006-10-01 03:38:04 +0000[diff] [blame]100Returns a boolean TRUE/FALSE. Usage example:</p>
101
102<code>
103if ($this->db->field_exists('field_name', 'table_name'))<br />
104{<br />
105&nbsp;&nbsp; // some code...<br />
106}
107</code>
108
admine334c472006-10-21 19:44:22 +0000[diff] [blame]109<p>Note: Replace <em>field_name</em> with the name of the column you are looking for, and replace
adminb2a9cec2006-10-01 03:38:04 +0000[diff] [blame]110<em>table_name</em> with the name of the table you are looking for.</p>
111
112
113
adminab4f61b2006-09-25 22:12:32 +0000[diff] [blame]114
admin194b8942006-10-04 07:59:32 +0000[diff] [blame]115<h2>$this->db->field_data()</h2>
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]116<p>Returns an array of objects containing field information.</p>
admin3dd978f2006-09-30 19:24:45 +0000[diff] [blame]117<p>Sometimes it's helpful to gather the field names or other metadata, like the column type, max length, etc.</p>
118
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]119
120<p class="important">Note: Not all databases provide meta-data.</p>
121
122<p>Usage example:</p>
123
124<code>
admin194b8942006-10-04 07:59:32 +0000[diff] [blame]125$fields = $this->db->field_data('table_name')<br /><br />
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]126
127foreach ($fields as $field)<br />
128{<br />
129&nbsp;&nbsp;&nbsp;echo $field->name;<br />
130&nbsp;&nbsp;&nbsp;echo $field->type;<br />
131&nbsp;&nbsp;&nbsp;echo $field->max_length;<br />
132&nbsp;&nbsp;&nbsp;echo $field->primary_key;<br />
133}
134</code>
135
admine7e1dcd2006-10-21 18:04:01 +0000[diff] [blame]136<p>If you have run a query already you can use the result object instead of supplying the table name:</p>
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]137
138<code>
admin194b8942006-10-04 07:59:32 +0000[diff] [blame]139$query = $this->db->query("YOUR QUERY")<br />
140$fields = $query->field_data()
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]141</code>
142
143
144<p>The following data is available from this function if supported by your database:</p>
145
146<ul>
147<li>name - column name</li>
148<li>max_length - maximum length of the column</li>
149<li>primary_key - 1 if the column is a primary key</li>
150<li>type - the type of the column</li>
151</ul>
152
153
154
155
156
157</div>
158<!-- END CONTENT -->
159
160
161<div id="footer">
162<p>
admind125c5c2006-09-25 23:26:12 +0000[diff] [blame]163Previous Topic:&nbsp;&nbsp;<a href="transactions.html">Transactions</a>
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]164&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;
165<a href="#top">Top of Page</a>&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;
166<a href="../index.html">User Guide Home</a>&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;
admind125c5c2006-09-25 23:26:12 +0000[diff] [blame]167Next Topic:&nbsp;&nbsp;<a href="call_function.html">Custom Function Calls</a>
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]168<p>
169<p><a href="http://www.codeigniter.com">Code Igniter</a> &nbsp;&middot;&nbsp; Copyright &#169; 2006 &nbsp;&middot;&nbsp; <a href="http://www.pmachine.com">pMachine, Inc.</a></p>
170</div>
171
172</body>
173</html>