Gitiles
Code Review Sign In
www.giggi.me / code-igniter-v3-giggi / bc03091cd30ae09a5156b66caa7cef4493569774 / . / user_guide / database / queries.html
blob: e55a5328a451fb64a286288b9b881d4910458644 [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
Derek Allardd2df9bc2007-04-15 17:41:17 +0000[diff] [blame]5<title>CodeIgniter User Guide</title>
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]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' />
Derek Allardd2df9bc2007-04-15 17:41:17 +0000[diff] [blame]25<meta name='description' content='CodeIgniter User Guide' />
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]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>
Derek Allardd2df9bc2007-04-15 17:41:17 +0000[diff] [blame]36<td><h1>CodeIgniter User Guide Version 1.5.3</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
44<!-- START BREADCRUMB -->
45<table cellpadding="0" cellspacing="0" border="0" style="width:100%">
46<tr>
47<td id="breadcrumb">
Derek Allardd2df9bc2007-04-15 17:41:17 +0000[diff] [blame]48<a href="http://www.codeigniter.com/">CodeIgniter Home</a> &nbsp;&#8250;&nbsp;
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]49<a href="../index.html">User Guide Home</a> &nbsp;&#8250;&nbsp;
50<a href="index.html">Database Library</a> &nbsp;&#8250;&nbsp;
51Queries
52</td>
Derek Allardbc030912007-06-24 18:25:29 +0000[diff] [blame^]53<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&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>
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]54</tr>
55</table>
56<!-- END BREADCRUMB -->
57
58
59
60<br clear="all" />
61
62
63<!-- START CONTENT -->
64<div id="content">
65
66
67<h1>Queries</h1>
68
69<h2>$this->db->query();</h2>
70
71<p>To submit a query, use the following function:</p>
72
73<code>$this->db->query('YOUR QUERY HERE');</code>
74
75<p>The <dfn>query()</dfn> function returns a database result <strong>object</strong> when "read" type queries are run,
76which you can use to <a href="results.html">show your results</a>. When "write" type queries are run it simply returns TRUE or FALSE
77depending on success or failure. When retrieving data you will typically assign the query to your own variable, like this:</p>
78
79<code><var>$query</var> = $this->db->query('YOUR QUERY HERE');</code>
80
81<h2>$this->db->simple_query();</h2>
82
83<p>This is a simplified version of the <dfn>$this->db->query()</dfn> function. It ONLY returns TRUE/FALSE on success or failure.
admine334c472006-10-21 19:44:22 +0000[diff] [blame]84It DOES NOT return a database result set, nor does it set the query timer, or compile bind data, or store your query for debugging.
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]85It simply lets you submit a query. Most users will rarely use this function.</p>
86
87
admin78ce3cc2006-10-02 02:58:03 +0000[diff] [blame]88<h1>Escaping Queries</h1>
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]89
admine334c472006-10-21 19:44:22 +0000[diff] [blame]90<p>It's a very good security practice to escape your data before submitting it into your database.
Derek Allardd2df9bc2007-04-15 17:41:17 +0000[diff] [blame]91CodeIgniter has two functions that help you do this:</p>
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]92
93<ol>
94</li>
admine334c472006-10-21 19:44:22 +0000[diff] [blame]95<li><strong>$this->db->escape()</strong> This function determines the data type so that it
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]96can escape only string data. It also automatically adds single quotes around the data so you don't have to:
97
98<code>$sql = "INSERT INTO table (title) VALUES(".$this->db->escape($title).")";</code>
99
100
admine334c472006-10-21 19:44:22 +0000[diff] [blame]101<li><strong>$this->db->escape_str()</strong> This function escapes the data passed to it, regardless of type.
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]102Most of the time you'll use the above function rather then this one. Use the function like this:
103
104<code>$sql = "INSERT INTO table (title) VALUES('".$this->db->escape_str($title)."')";</code>
105
106</li>
107</ol>
108
109
admin78ce3cc2006-10-02 02:58:03 +0000[diff] [blame]110<h1>Query Bindings</h1>
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]111
112
113<p>Bindings enable you to simplify your query syntax by letting the system put the queries together for you. Consider the following example:</p>
114
115<code>
116$sql = "SELECT * FROM some_table WHERE id = <var>?</var> AND status = <var>?</var> AND author = <var>?</var>";
117<br /><br />
118$this->db->query($sql, array(3, 'live', 'Rick'));
119</code>
120
121<p>The question marks in the query are automatically replaced with the values in the array in the second parameter of the query function.</p>
122<p class="important">The secondary benefit of using binds is that the values are automatically escaped, producing safer queries. You don't have to remember to manually escape data; the engine does it automatically for you.</p>
123
124
125
126</div>
127<!-- END CONTENT -->
128
129
130<div id="footer">
131<p>
132Previous Topic:&nbsp;&nbsp;<a href="connecting.html">Connecting to your Database</a>
133&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;
134<a href="#top">Top of Page</a>&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;
135<a href="../index.html">User Guide Home</a>&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;
136Next Topic:&nbsp;&nbsp;<a href="results.html">Query Results</a>
137<p>
Derek Allardd2df9bc2007-04-15 17:41:17 +0000[diff] [blame]138<p><a href="http://www.codeigniter.com">CodeIgniter</a> &nbsp;&middot;&nbsp; Copyright &#169; 2007 &nbsp;&middot;&nbsp; <a href="http://ellislab.com/">Ellislab, Inc.</a></p>
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]139</div>
140
141</body>
142</html>