Gitiles
Code Review Sign In
www.giggi.me / code-igniter-v3-giggi / 58e8caf2afb3ea054f83999fb0698720a1a58738 / . / user_guide / database / results.html
blob: e9a5cb4cfb7694562bf180f1deeb4bbf611c36e9 [file] [log] [blame]
Derek Allard2067d1a2008-11-13 22:59:24 +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 xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
3<head>
4
5<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
6<title>Generating Query Results : CodeIgniter User Guide</title>
7
8<style type='text/css' media='all'>@import url('../userguide.css');</style>
9<link rel='stylesheet' type='text/css' media='all' href='../userguide.css' />
10
11<script type="text/javascript" src="../nav/nav.js"></script>
12<script type="text/javascript" src="../nav/prototype.lite.js"></script>
13<script type="text/javascript" src="../nav/moo.fx.js"></script>
14<script type="text/javascript" src="../nav/user_guide_menu.js"></script>
15
16<meta http-equiv='expires' content='-1' />
17<meta http-equiv= 'pragma' content='no-cache' />
18<meta name='robots' content='all' />
19<meta name='author' content='ExpressionEngine Dev Team' />
20<meta name='description' content='CodeIgniter User Guide' />
21
22</head>
23<body>
24
25<!-- START NAVIGATION -->
26<div id="nav"><div id="nav_inner"><script type="text/javascript">create_menu('../');</script></div></div>
27<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>
28<div id="masthead">
29<table cellpadding="0" cellspacing="0" border="0" style="width:100%">
30<tr>
Derek Jones8917af72010-03-05 12:41:45 -0600[diff] [blame]31<td><h1>CodeIgniter User Guide Version 2.0.0</h1></td>
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]32<td id="breadcrumb_right"><a href="../toc.html">Table of Contents Page</a></td>
33</tr>
34</table>
35</div>
36<!-- END NAVIGATION -->
37
38
39<!-- START BREADCRUMB -->
40<table cellpadding="0" cellspacing="0" border="0" style="width:100%">
41<tr>
42<td id="breadcrumb">
43<a href="http://codeigniter.com/">CodeIgniter Home</a> &nbsp;&#8250;&nbsp;
44<a href="../index.html">User Guide Home</a> &nbsp;&#8250;&nbsp;
45<a href="index.html">Database Library</a> &nbsp;&#8250;&nbsp;
46Query Results
47</td>
48<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>
49</tr>
50</table>
51<!-- END BREADCRUMB -->
52
53
54<br clear="all" />
55
56
57<!-- START CONTENT -->
58<div id="content">
59
60
61
62<h1>Generating Query Results</h1>
63
64
65<p>There are several ways to generate query results:</p>
66
67 <h2>result()</h2>
Barry Mienydd671972010-10-04 16:33:58 +0200[diff] [blame]68
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]69 <p>This function returns the query result as an array of <strong>objects</strong>, or <strong>an empty array</strong> on failure.
Barry Mienydd671972010-10-04 16:33:58 +0200[diff] [blame]70
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]71 Typically you'll use this in a foreach loop, like this:</p>
Barry Mienydd671972010-10-04 16:33:58 +0200[diff] [blame]72
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]73 <code>
74 $query = $this->db->query("YOUR QUERY");<br />
75 <br />
76 foreach ($query->result() as $row)<br />
77 {<br />
78 &nbsp;&nbsp;&nbsp;echo $row->title;<br />
79 &nbsp;&nbsp;&nbsp;echo $row->name;<br />
80 &nbsp;&nbsp;&nbsp;echo $row->body;<br />
81 }</code>
Barry Mienydd671972010-10-04 16:33:58 +0200[diff] [blame]82
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]83 <p>The above <dfn>function</dfn> is an alias of <dfn>result_object()</dfn>.</p>
84
85 <p>If you run queries that might <strong>not</strong> produce a result, you are encouraged to test the result first:</p>
Barry Mienydd671972010-10-04 16:33:58 +0200[diff] [blame]86
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]87 <code>
88 $query = $this->db->query("YOUR QUERY");<br />
89 <br />
90 if ($query->num_rows() > 0)<br />
91 {<br />
92 &nbsp;&nbsp;&nbsp;foreach ($query->result() as $row)<br />
93 &nbsp;&nbsp;&nbsp;{<br />
94 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;echo $row->title;<br />
95 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;echo $row->name;<br />
96 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;echo $row->body;<br />
97 &nbsp;&nbsp;&nbsp;}<br />
98 }
99 </code>
Barry Mienydd671972010-10-04 16:33:58 +0200[diff] [blame]100
John Crepezzi58e8caf2011-02-05 22:19:57 -0500[diff] [blame^]101 <p>You can also pass a string to result() which represents a class to instantiate for each result object (note: this class must be loaded)</p>
102
103 <code>
104 $query = $this->db->query("SELECT * FROM users;");<br />
105 <br />
106 foreach ($query->result('User') as $user)<br />
107 {<br />
108 &nbsp;&nbsp;&nbsp;echo $row->name; // call attributes<br />
109 &nbsp;&nbsp;&nbsp;echo $row->reverse_name(); // or methods defined on the 'User' class<br />
110 }
111 </code>
112
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]113 <h2>result_array()</h2>
Barry Mienydd671972010-10-04 16:33:58 +0200[diff] [blame]114
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]115 <p>This function returns the query result as a pure array, or an empty array when no result is produced. Typically you'll use this in a foreach loop, like this:</p>
116 <code>
117 $query = $this->db->query("YOUR QUERY");<br />
118 <br />
119 foreach ($query->result_array() as $row)<br />
120 {<br />
121 &nbsp;&nbsp;&nbsp;echo $row['title'];<br />
122 &nbsp;&nbsp;&nbsp;echo $row['name'];<br />
123 &nbsp;&nbsp;&nbsp;echo $row['body'];<br />
124 }</code>
125
126
127 <h2>row()</h2>
Barry Mienydd671972010-10-04 16:33:58 +0200[diff] [blame]128
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]129 <p>This function returns a single result row. If your query has more than one row, it returns only the first row.
130 The result is returned as an <strong>object</strong>. Here's a usage example:</p>
131 <code>
132 $query = $this->db->query("YOUR QUERY");<br />
133 <br />
134 if ($query->num_rows() > 0)<br />
135 {<br />
136 &nbsp;&nbsp;&nbsp;$row = $query->row();
137 <br /><br />
138 &nbsp;&nbsp;&nbsp;echo $row->title;<br />
139 &nbsp;&nbsp;&nbsp;echo $row->name;<br />
140 &nbsp;&nbsp;&nbsp;echo $row->body;<br />
141 }
142 </code>
Barry Mienydd671972010-10-04 16:33:58 +0200[diff] [blame]143
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]144 <p>If you want a specific row returned you can submit the row number as a digit in the first parameter:</p>
Barry Mienydd671972010-10-04 16:33:58 +0200[diff] [blame]145
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]146 <code>$row = $query->row(<dfn>5</dfn>);</code>
147
John Crepezzi58e8caf2011-02-05 22:19:57 -0500[diff] [blame^]148 <p>You can also add a second String parameter, which is the name of a class to instantiate the row with:</p>
149
150 <code>
151 $query = $this->db->query("SELECT * FROM users LIMIT 1;");<br />
152 <br />
153 $query->row(0, 'User')<br />
154 echo $row->name; // call attributes<br />
155 echo $row->reverse_name(); // or methods defined on the 'User' class<br />
156 </code>
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]157
158 <h2>row_array()</h2>
159
160 <p>Identical to the above <var>row()</var> function, except it returns an array. Example:</p>
161
162 <code>
163 $query = $this->db->query("YOUR QUERY");<br />
164 <br />
165 if ($query->num_rows() > 0)<br />
166 {<br />
167 &nbsp;&nbsp;&nbsp;$row = $query->row_array();
168 <br /><br />
169 &nbsp;&nbsp;&nbsp;echo $row['title'];<br />
170 &nbsp;&nbsp;&nbsp;echo $row['name'];<br />
171 &nbsp;&nbsp;&nbsp;echo $row['body'];<br />
172 }
173 </code>
174
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]175
Barry Mienydd671972010-10-04 16:33:58 +0200[diff] [blame]176 <p>If you want a specific row returned you can submit the row number as a digit in the first parameter:</p>
177
178 <code>$row = $query->row_array(<dfn>5</dfn>);</code>
179
180
181 <p>In addition, you can walk forward/backwards/first/last through your results using these variations:</p>
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]182
183<p>
184 <strong>$row = $query->first_row()</strong><br />
185 <strong>$row = $query->last_row()</strong><br />
186 <strong>$row = $query->next_row()</strong><br />
187 <strong>$row = $query->previous_row()</strong>
188</p>
189
190<p>By default they return an object unless you put the word "array" in the parameter:</p>
191
192<p>
193 <strong>$row = $query->first_row('array')</strong><br />
194 <strong>$row = $query->last_row('array')</strong><br />
195 <strong>$row = $query->next_row('array')</strong><br />
196 <strong>$row = $query->previous_row('array')</strong>
197</p>
198
199
200
201<h1>Result Helper Functions</h1>
202
203
204<h2>$query->num_rows()</h2>
205<p>The number of rows returned by the query. Note: In this example, <dfn>$query</dfn> is the variable that the query result object is assigned to:</p>
206
207<code>$query = $this->db->query('SELECT * FROM my_table');<br /><br />
208echo $query->num_rows();
209</code>
210
211<h2>$query->num_fields()</h2>
212<p>The number of FIELDS (columns) returned by the query. Make sure to call the function using your query result object:</p>
213
214<code>$query = $this->db->query('SELECT * FROM my_table');<br /><br />
215echo $query->num_fields();
216</code>
217
218
219
220<h2>$query->free_result()</h2>
221<p>It frees the memory associated with the result and deletes the result resource ID. Normally PHP frees its memory automatically at the end of script
222execution. However, if you are running a lot of queries in a particular script you might want to free the result after each query result has been
223generated in order to cut down on memory consumptions. Example:
224</p>
225
226<code>$query = $this->db->query('SELECT title FROM my_table');<br /><br />
227foreach ($query->result() as $row)<br />
228{<br />
229&nbsp;&nbsp;&nbsp;echo $row->title;<br />
230}<br />
231$query->free_result(); // The $query result object will no longer be available<br />
232<br />
233$query2 = $this->db->query('SELECT name FROM some_table');<br /><br />
234$row = $query2->row();<br />
235echo $row->name;<br />
236$query2->free_result(); // The $query2 result object will no longer be available
237</code>
238
239
240
Barry Mienydd671972010-10-04 16:33:58 +0200[diff] [blame]241
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]242
243</div>
244<!-- END CONTENT -->
245
246
247<div id="footer">
248<p>
249Previous Topic:&nbsp;&nbsp;<a href="queries.html">Queries</a>
250&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;
251<a href="#top">Top of Page</a>&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;
252<a href="../index.html">User Guide Home</a>&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;
253Next Topic:&nbsp;&nbsp;<a href="helpers.html">Query Helper Functions</a>
254</p>
Derek Jones700205a2011-01-28 07:44:28 -0600[diff] [blame]255<p><a href="http://codeigniter.com">CodeIgniter</a> &nbsp;&middot;&nbsp; Copyright &#169; 2006 - 2011 &nbsp;&middot;&nbsp; <a href="http://ellislab.com/">EllisLab, Inc.</a></p>
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]256</div>
257
258</body>
John Crepezzi58e8caf2011-02-05 22:19:57 -0500[diff] [blame^]259</html>