Question

I am working with a table that contains logs for users reported exercise distances. I want to rank users by the sum of their logged distance.

First I find all the User ID’s:

select distinct wordpress_user_id from wp_exercise_log

Then I loop through that and get the name and sum(distance) with:

    foreach($users as $user) {
// DISTANCE
    $user_distance = floor($wpdb->get_var( "select sum(distance) from wp_exercise_log where wordpress_user_id='$user'"));
// FULL NAME
  $user_info = get_userdata($user);
  $full_name = $user_info-> user_firstname . ' ' . $user_info-> user_lastname;
}

Heres my problem: Unless I append them to a multidimensional array and sort with PHP, I’m not sure how I can rank the users.

Is there a better way to select all this data and sort it with one SQL query?

Answer 1

select
   wordpress_user_id, 
   sum(distance) as user_distance 
from 
   wp_exercise_log 
group by 
   wordpress_user_id 
order by 
   user_distance desc

Please mind ORDER BY GROUP_FUNCTION() is always causing perfomance issues.

You may consider to add some column user_total_distance to your users table and update it every change in wp_exercise_log.