Getting last run SQL from CodeIgniter's DB class

Here's a convenient way to obtain the last executed SQL query when using CodeIgniter's database class.

Code snippet for this example:

$this->db->select('status');
$this->db->from('tbl_user');
$this->db->where('user_id', $user_id);

$results = $this->db->get();

echo $this->db->last_query();

The last call to last_query() will output the actual SQL executed.

Logging request parameters in CodeIgniter

The application I'm currently working on provides services to mobile devices.  As such, I need to constantly check what values the mobile devices are POST-ing to the application.  Instead of adding a call to all functions in the controllers to perform this task, I decided to implement a hook in the application.

Hooks are supported in CodeIgniter (more info here).  Here's my hook class to perform the logging:

class Logger {
   
    private $CI;
   
    public function __construct() {
        $this->CI =& get_instance();
    }
   
    public function request_logger() {
        $uri = $this->CI->uri->uri_string();
       
            $params = trim(print_r($this->CI->input->post(), TRUE));
       
        log_message('info', '==============');
        log_message('info', 'URI: ' . $uri);
        log_message('info', '--------------');
        log_message('info', $params);
        log_message('info', '==============');
    }
}

To enable hooks, you'll need to edit the config/hooks.php file.  Here's the content of the file to enable the Logger class above:

$hook['post_controller_constructor'] = array(
                                'class'    => 'Logger',
                                'function' => 'request_logger',
                                'filename' => 'Logger.php',
                                'filepath' => 'hooks'
                            );

I chose to use "post_controller_constructor" as it is called before any methods in the controller class is executed.

Output below shows how the output looks like from the application logs:

INFO  - 2011-12-15 05:09:24 --> URI: services/promos/add_comment
INFO  - 2011-12-15 05:09:24 --> Array
(
    [param1] => value1
    [id] => dj3243hasdgasdg
    [msg] => Testing testing
)