How to Updating an existing database record +1 in CodeIgniter?

Last updated on December 1, 2014

$the->db->set() – This function enables you to set values for inserts or updates.
$this->db->where() – This function enables you to set WHERE clauses
$this->db->update() – Generates an update string and runs the query based on the data you supply

Don’t forgot to set the third parameter for $the->db->set to FALSE in order to escape

$this->db->set('views', 'views + 1',FALSE); 
$this->db->where('id', $id); 
this->db->update('articles'); 
// gives INSERT INTO articles (views) VALUES (views+1) 
// without optional third parameter ($escape) False , gives INSERT INTO articles (views) VALUES ('views+1') 

Reference : http://ellislab.com/codeigniter/user-guide/database/active_record.html