Codeigniter's active record ignoring everything after “/”

issue

User inputs data like a/b

code we use to save the data

PHP Code:

<?php
    $text = $this->input->post('user_input');
    $data = array('text'=>$text);
    $this->db->insert('table_name',$data);
?>

problem

data which is saved in the database is a/ nothing after / data after / is not saved in the db

note

db column size is not any issue since it is varchar and size 10