Query Drupal User Table for: date created < $today - '100000' - drupal-7

Question

I would like to select users from the Drupal users table where the date created was older than 1 day ago. Then delete those users. This code isn't correct but it will give you an idea of what I am trying to do I just don't know the right DB query.
'
$users = db_select('user', 'created') //I know this is not the right DB query
$count = count($users);
if($count > 0){
$users = user_load_multiple(array_keys($users['user']));
}
$today = getdate();
if ($users < $today - '100000' ) {
user_delete($user->uid)
}
I am thinking about using user_load_multiple() to load the users in to an array to perform the delete action.

Answer 1

Get an array with the uids of the users you want to delete and use user_delete_multiple($arrayOfUidToDelete) : https://api.drupal.org/api/drupal/modules!user!user.module/function/user_delete_multiple/7
Using the function user_load_multiple() can be heavy on ressources if you have a lot of users and you will end with PHP errors (out of memory...).
Plus you don't need to load the users, you just want to delete them.
For the query I will go with db_query instead of db_select if there is no parameters valued by an user (better performances).
So it will look something like :
//get the list of uid
$user_list = db_query("select uid
from users
where CAST(FROM_UNIXTIME(created) as date) < NOW() - INTERVAL 1 DAY"
)->fetchCol();
// delete the users
user_delete_multiple($user_list);