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+#####################
+Custom Function Calls
+#####################
+
+$this->db->call_function();
+============================
+
+This function enables you to call PHP database functions that are not
+natively included in CodeIgniter, in a platform independent manner. For
+example, lets say you want to call the mysql_get_client_info()
+function, which is **not** natively supported by CodeIgniter. You could
+do so like this::
+
+	$this->db->call_function('get_client_info');
+
+You must supply the name of the function, **without** the mysql\_
+prefix, in the first parameter. The prefix is added automatically based
+on which database driver is currently being used. This permits you to
+run the same function on different database platforms. Obviously not all
+function calls are identical between platforms, so there are limits to
+how useful this function can be in terms of portability.
+
+Any parameters needed by the function you are calling will be added to
+the second parameter.
+
+::
+
+	$this->db->call_function('some_function', $param1, $param2, etc..);
+
+Often, you will either need to supply a database connection ID or a
+database result ID. The connection ID can be accessed using::
+
+	$this->db->conn_id;
+
+The result ID can be accessed from within your result object, like this::
+
+	$query = $this->db->query("SOME QUERY");  $query->result_id;
+