Trying to count all records from database

I think I am almost there with this.

I currently have the following in the database:

page_hits  |  date            |    pageid
5                |  2017-09-14   |  testing
5                |  2017-09-01   |  testing

and on the page I am wanting it to have 

pageid   |  page_hits
testing     |  10

But instead I am getting:

pageid   |  page_hits
testing     |  2

Here is  how far I have got my code to:

PHP Code:

$date = new DateTime('FIRST DAY OF 0 MONTHS');
    $pm =  $date->format('n'); 
    $pmy = $date->format('Y'); 
    $this->db->select('*, COUNT(page_hits) as page_hits');
    $this->db->from('analytics_page_views');
    $this->db->where('MONTH(date)', $pm);
    $this->db->where('YEAR(date)', $pmy);
    $this->db->group_by('pageid');
    $query = $this->db->get();
    return $query->result();       


So i know that its using the page_hits as how many rows their is but not adding the values in page_hits together.