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Derek Jonesfd93d222008-05-06 15:18:50 +0000[diff] [blame^]5<title>Generating Query Results : CodeIgniter User Guide</title>
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Derek Allard197d10b2008-02-12 04:20:38 +0000[diff] [blame]31<td><h1>CodeIgniter User Guide Version 1.6.1</h1></td>
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Derek Jones7a9193a2008-01-21 18:39:20 +0000[diff] [blame]43<a href="http://codeigniter.com/">CodeIgniter Home</a> &nbsp;&#8250;&nbsp;
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45<a href="index.html">Database Library</a> &nbsp;&#8250;&nbsp;
46Query Results
47</td>
Derek Allardbc030912007-06-24 18:25:29 +0000[diff] [blame]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>
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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>
68
Derek Allard11b76a32007-02-02 03:46:31 +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.
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]70
71 Typically you'll use this in a foreach loop, like this:</p>
72
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>
adminb2a9cec2006-10-01 03:38:04 +0000[diff] [blame]82
83 <p>The above <dfn>function</dfn> is an alias of <dfn>result_object()</dfn>.</p>
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]84
85 <p>If you run queries that might <strong>not</strong> produce a result, you are encouraged to test the result first:</p>
86
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>
100
101 <h2>result_array()</h2>
102
Derek Allard67e10532007-02-24 15:13:17 +0000[diff] [blame]103 <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>
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]104 <code>
105 $query = $this->db->query("YOUR QUERY");<br />
106 <br />
107 foreach ($query->result_array() as $row)<br />
108 {<br />
109 &nbsp;&nbsp;&nbsp;echo $row['title'];<br />
110 &nbsp;&nbsp;&nbsp;echo $row['name'];<br />
111 &nbsp;&nbsp;&nbsp;echo $row['body'];<br />
112 }</code>
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]113
114
115 <h2>row()</h2>
116
admine334c472006-10-21 19:44:22 +0000[diff] [blame]117 <p>This function returns a single result row. If your query has more than one row, it returns only the first row.
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]118 The result is returned as an <strong>object</strong>. Here's a usage example:</p>
119 <code>
120 $query = $this->db->query("YOUR QUERY");<br />
121 <br />
122 if ($query->num_rows() > 0)<br />
123 {<br />
124 &nbsp;&nbsp;&nbsp;$row = $query->row();
125 <br /><br />
126 &nbsp;&nbsp;&nbsp;echo $row->title;<br />
127 &nbsp;&nbsp;&nbsp;echo $row->name;<br />
128 &nbsp;&nbsp;&nbsp;echo $row->body;<br />
129 }
130 </code>
131
Derek Allardc6441282007-07-04 23:54:32 +0000[diff] [blame]132 <p>If you want a specific row returned you can submit the row number as a digit in the first parameter:</p>
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]133
134 <code>$row = $query->row(<dfn>5</dfn>);</code>
135
136
137 <h2>row_array()</h2>
138
139 <p>Identical to the above <var>row()</var> function, except it returns an array. Example:</p>
140
141 <code>
142 $query = $this->db->query("YOUR QUERY");<br />
143 <br />
144 if ($query->num_rows() > 0)<br />
145 {<br />
146 &nbsp;&nbsp;&nbsp;$row = $query->row_array();
147 <br /><br />
148 &nbsp;&nbsp;&nbsp;echo $row['title'];<br />
149 &nbsp;&nbsp;&nbsp;echo $row['name'];<br />
150 &nbsp;&nbsp;&nbsp;echo $row['body'];<br />
151 }
152 </code>
153
154
Derek Allardc6441282007-07-04 23:54:32 +0000[diff] [blame]155 <p>If you want a specific row returned you can submit the row number as a digit in the first parameter:</p>
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]156
157 <code>$row = $query->row_array(<dfn>5</dfn>);</code>
158
admine334c472006-10-21 19:44:22 +0000[diff] [blame]159
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]160 <p>In addition, you can walk forward/backwards/first/last through your results using these variations:</p>
161
162<p>
163 <strong>$row = $query->first_row()</strong><br />
164 <strong>$row = $query->last_row()</strong><br />
165 <strong>$row = $query->next_row()</strong><br />
166 <strong>$row = $query->previous_row()</strong>
167</p>
168
169<p>By default they return an object unless you put the word "array" in the parameter:</p>
170
171<p>
172 <strong>$row = $query->first_row('array')</strong><br />
173 <strong>$row = $query->last_row('array')</strong><br />
174 <strong>$row = $query->next_row('array')</strong><br />
175 <strong>$row = $query->previous_row('array')</strong>
176</p>
177
178
Derek Allardc6441282007-07-04 23:54:32 +0000[diff] [blame]179
admin78ce3cc2006-10-02 02:58:03 +0000[diff] [blame]180<h1>Result Helper Functions</h1>
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]181
182
183<h2>$query->num_rows()</h2>
184<p>The number of rows returned by the query. Note: In this example, <dfn>$query</dfn> is the variable that the query result object is assigned to:</p>
185
186<code>$query = $this->db->query('SELECT * FROM my_table');<br /><br />
187echo $query->num_rows();
188</code>
189
190<h2>$query->num_fields()</h2>
191<p>The number of FIELDS (columns) returned by the query. Make sure to call the function using your query result object:</p>
192
193<code>$query = $this->db->query('SELECT * FROM my_table');<br /><br />
194echo $query->num_fields();
195</code>
196
197
198
adminddf83e42006-09-24 20:25:42 +0000[diff] [blame]199<h2>$query->free_result()</h2>
200<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
201execution. 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
202generated in order to cut down on memory consumptions. Example:
203</p>
204
205<code>$query = $this->db->query('SELECT title FROM my_table');<br /><br />
206foreach ($query->result() as $row)<br />
207{<br />
208&nbsp;&nbsp;&nbsp;echo $row->title;<br />
209}<br />
210$query->free_result(); // The $query result object will no longer be available<br />
211<br />
212$query2 = $this->db->query('SELECT name FROM some_table');<br /><br />
213$row = $query2->row();<br />
214echo $row->name;<br />
215$query2->free_result(); // The $query2 result object will no longer be available
216</code>
217
218
219
adminfb28bb82006-09-24 17:59:33 +0000[diff] [blame]220
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Derek Allardc6441282007-07-04 23:54:32 +0000[diff] [blame]233</p>
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