How to empty or truncate mysql table using codeigniter active record?

If you want to empty or truncate a mysql table using Codeigniter active record, use the following code.
To empty

$this->db->empty_table();

This will generate a delete SQL string and runs the query.

// DELETE FROM mytable

To truncate

$this->db->from('mytable'); 
$this->db->truncate(); 
// or 
$this->db->truncate('mytable');

This will generate a truncate SQL string and runs the query.

// TRUNCATE mytable 

Source: http://www.learnhow2do.com/computer/internet/2013/04/13/learn-how-to-empty-or-truncate-table-using-codeigniter-active-record/