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62 <h1>Generating Query Results</h1>
65 <p>There are several ways to generate query results:</p>
69 <p>This function returns the query result as an array of <strong>objects</strong>, or <strong>an empty array</strong> on failure.
71 Typically you'll use this in a foreach loop, like this:</p>
74 $query = $this->db->query("YOUR QUERY");<br />
76 foreach ($query->result() as $row)<br />
78 echo $row->title;<br />
79 echo $row->name;<br />
80 echo $row->body;<br />
83 <p>The above <dfn>function</dfn> is an alias of <dfn>result_object()</dfn>.</p>
85 <p>If you run queries that might <strong>not</strong> produce a result, you are encouraged to test the result first:</p>
88 $query = $this->db->query("YOUR QUERY");<br />
90 if ($query->num_rows() > 0)<br />
92 foreach ($query->result() as $row)<br />
93 {<br />
94 echo $row->title;<br />
95 echo $row->name;<br />
96 echo $row->body;<br />
97 }<br />
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>
104 $query = $this->db->query("SELECT * FROM users;");<br />
106 foreach ($query->result('User') as $user)<br />
108 echo $row->name; // call attributes<br />
109 echo $row->reverse_name(); // or methods defined on the 'User' class<br />
113 <h2>result_array()</h2>
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>
117 $query = $this->db->query("YOUR QUERY");<br />
119 foreach ($query->result_array() as $row)<br />
121 echo $row['title'];<br />
122 echo $row['name'];<br />
123 echo $row['body'];<br />
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>
132 $query = $this->db->query("YOUR QUERY");<br />
134 if ($query->num_rows() > 0)<br />
136 $row = $query->row();
138 echo $row->title;<br />
139 echo $row->name;<br />
140 echo $row->body;<br />
144 <p>If you want a specific row returned you can submit the row number as a digit in the first parameter:</p>
146 <code>$row = $query->row(<dfn>5</dfn>);</code>
148 <p>You can also add a second String parameter, which is the name of a class to instantiate the row with:</p>
151 $query = $this->db->query("SELECT * FROM users LIMIT 1;");<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 />
160 <p>Identical to the above <var>row()</var> function, except it returns an array. Example:</p>
163 $query = $this->db->query("YOUR QUERY");<br />
165 if ($query->num_rows() > 0)<br />
167 $row = $query->row_array();
169 echo $row['title'];<br />
170 echo $row['name'];<br />
171 echo $row['body'];<br />
176 <p>If you want a specific row returned you can submit the row number as a digit in the first parameter:</p>
178 <code>$row = $query->row_array(<dfn>5</dfn>);</code>
181 <p>In addition, you can walk forward/backwards/first/last through your results using these variations:</p>
184 <strong>$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 = $query->previous_row()</strong>
190 <p>By default they return an object unless you put the word "array" in the parameter:</p>
193 <strong>$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 = $query->previous_row('array')</strong>
201 <h1>Result Helper Functions</h1>
204 <h2>$query->num_rows()</h2>
205 <p>The number of rows returned by the query. Note: In this example, <dfn>$query</dfn> is the variable that the query result object is assigned to:</p>
207 <code>$query = $this->db->query('SELECT * FROM my_table');<br /><br />
208 echo $query->num_rows();
211 <h2>$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>
214 <code>$query = $this->db->query('SELECT * FROM my_table');<br /><br />
215 echo $query->num_fields();
220 <h2>$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
222 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
223 generated in order to cut down on memory consumptions. Example:
226 <code>$query = $this->db->query('SELECT title FROM my_table');<br /><br />
227 foreach ($query->result() as $row)<br />
229 echo $row->title;<br />
231 $query->free_result(); // The $query result object will no longer be available<br />
233 $query2 = $this->db->query('SELECT name FROM some_table');<br /><br />
234 $row = $query2->row();<br />
235 echo $row->name;<br />
236 $query2->free_result(); // The $query2 result object will no longer be available
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