Update the value of a field in database by 1 using codeigniter

Question

I want to implement a SQL statement using codeigniter active record.

UPDATE tags SET usage = usage+1 WHERE tag=\"java\";

How can I implemen

Answer 1

$this->db->set('usage', 'usage+1', FALSE);
$this->db->where('tag', 'java');
$this->db->update('tags');