1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
|
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<head>
<title>Code Igniter 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">
window.onload = function() {
myHeight = new fx.Height('nav', {duration: 400});
myHeight.hide();
}
</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='Rick Ellis' />
<meta name='description' content='Code Igniter 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>Code Igniter User Guide Version 1.5.2</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://www.codeigniter.com/">Code Igniter Home</a> ›
<a href="../index.html">User Guide Home</a> ›
<a href="index.html">Database Library</a> ›
Query Results
</td>
<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 <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>Generating Query Results</h1>
<p>There are several ways to generate query results:</p>
<h2>result()</h2>
<p>This function returns the query result as an array of <strong>objects</strong>, or <strong>an empty array</strong> on failure.
Typically you'll use this in a foreach loop, like this:</p>
<code>
$query = $this->db->query("YOUR QUERY");<br />
<br />
foreach ($query->result() as $row)<br />
{<br />
echo $row->title;<br />
echo $row->name;<br />
echo $row->body;<br />
}</code>
<p>The above <dfn>function</dfn> is an alias of <dfn>result_object()</dfn>.</p>
<p>If you run queries that might <strong>not</strong> produce a result, you are encouraged to test the result first:</p>
<code>
$query = $this->db->query("YOUR QUERY");<br />
<br />
if ($query->num_rows() > 0)<br />
{<br />
foreach ($query->result() as $row)<br />
{<br />
echo $row->title;<br />
echo $row->name;<br />
echo $row->body;<br />
}<br />
}
</code>
<h2>result_array()</h2>
<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>
<code>
$query = $this->db->query("YOUR QUERY");<br />
<br />
foreach ($query->result_array() as $row)<br />
{<br />
echo $row['title'];<br />
echo $row['name'];<br />
echo $row['body'];<br />
}</code>
<h2>row()</h2>
<p>This function returns a single result row. If your query has more than one row, it returns only the first row.
The result is returned as an <strong>object</strong>. Here's a usage example:</p>
<code>
$query = $this->db->query("YOUR QUERY");<br />
<br />
if ($query->num_rows() > 0)<br />
{<br />
$row = $query->row();
<br /><br />
echo $row->title;<br />
echo $row->name;<br />
echo $row->body;<br />
}
</code>
<p>If you want a specific row returned you can submit the row number as a digit in the first parameter:
<code>$row = $query->row(<dfn>5</dfn>);</code>
<h2>row_array()</h2>
<p>Identical to the above <var>row()</var> function, except it returns an array. Example:</p>
<code>
$query = $this->db->query("YOUR QUERY");<br />
<br />
if ($query->num_rows() > 0)<br />
{<br />
$row = $query->row_array();
<br /><br />
echo $row['title'];<br />
echo $row['name'];<br />
echo $row['body'];<br />
}
</code>
<p>If you want a specific row returned you can submit the row number as a digit in the first parameter:
<code>$row = $query->row_array(<dfn>5</dfn>);</code>
<p>In addition, you can walk forward/backwards/first/last through your results using these variations:</p>
<p>
<strong>$row = $query->first_row()</strong><br />
<strong>$row = $query->last_row()</strong><br />
<strong>$row = $query->next_row()</strong><br />
<strong>$row = $query->previous_row()</strong>
</p>
<p>By default they return an object unless you put the word "array" in the parameter:</p>
<p>
<strong>$row = $query->first_row('array')</strong><br />
<strong>$row = $query->last_row('array')</strong><br />
<strong>$row = $query->next_row('array')</strong><br />
<strong>$row = $query->previous_row('array')</strong>
</p>
<br />
<h1>Result Helper Functions</h1>
<h2>$query->num_rows()</h2>
<p>The number of rows returned by the query. Note: In this example, <dfn>$query</dfn> is the variable that the query result object is assigned to:</p>
<code>$query = $this->db->query('SELECT * FROM my_table');<br /><br />
echo $query->num_rows();
</code>
<h2>$query->num_fields()</h2>
<p>The number of FIELDS (columns) returned by the query. Make sure to call the function using your query result object:</p>
<code>$query = $this->db->query('SELECT * FROM my_table');<br /><br />
echo $query->num_fields();
</code>
<h2>$query->free_result()</h2>
<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
execution. 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
generated in order to cut down on memory consumptions. Example:
</p>
<code>$query = $this->db->query('SELECT title FROM my_table');<br /><br />
foreach ($query->result() as $row)<br />
{<br />
echo $row->title;<br />
}<br />
$query->free_result(); // The $query result object will no longer be available<br />
<br />
$query2 = $this->db->query('SELECT name FROM some_table');<br /><br />
$row = $query2->row();<br />
echo $row->name;<br />
$query2->free_result(); // The $query2 result object will no longer be available
</code>
</div>
<!-- END CONTENT -->
<div id="footer">
<p>
Previous Topic: <a href="queries.html">Queries</a>
·
<a href="#top">Top of Page</a> ·
<a href="../index.html">User Guide Home</a> ·
Next Topic: <a href="helpers.html">Query Helper Functions</a>
<p>
<p><a href="http://www.codeigniter.com">Code Igniter</a> · Copyright © 2006 · <a href="http://ellislab.com/">Ellislab, Inc.</a></p>
</div>
</body>
</html>
|
