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Derek Jones733310d2009-02-11 01:13:43 +0000[diff] [blame]31<td><h1>CodeIgniter User Guide Version 1.7.1</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>
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45<a href="index.html">Database Library</a> &nbsp;&#8250;&nbsp;
46Query Results
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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
69 <p>This function returns the query result as an array of <strong>objects</strong>, or <strong>an empty array</strong> on failure.
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>
82
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>
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
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>
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>
113
114
115 <h2>row()</h2>
116
117 <p>This function returns a single result row. If your query has more than one row, it returns only the first row.
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 $row->body;<br />
129 }
130 </code>
131
132 <p>If you want a specific row returned you can submit the row number as a digit in the first parameter:</p>
133
134 <code>$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 $row['body'];<br />
151 }
152 </code>
153
154
155 <p>If you want a specific row returned you can submit the row number as a digit in the first parameter:</p>
156
157 <code>$row = $query->row_array(<dfn>5</dfn>);</code>
158
159
160 <p>In addition, you can walk forward/backwards/first/last through your results using these variations:</p>
161
162<p>
163 <strong>$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 = $query->previous_row('array')</strong>
176</p>
177
178
179
180<h1>Result Helper Functions</h1>
181
182
183<h2>$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 $query->num_fields();
195</code>
196
197
198
199<h2>$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
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