WordPress posts orderby meta value with strings and numbers - php

Question

I have a custom field (advanced custom field) called custom_order and I want WordPress to sort all posts by the field values.
The custom_order field's values can be written in 3 ways:
numbers only (3, 400, 6424)
numbers, then strings (3A, 3B, 5000A)
numbers, then strings, then numbers (3A1, 3A2, 401AZ1, 9000A3, 9000A1)
More examples of custom_order values:
Wanted order:
1, 2, 3, 3A, 3B, 3C, 3CA, 4, 400, 401, 401A, 401AZ, 401Z, 9000, 9000A, 9000A1, 9000A3
Conditions:
3 should come before 200 (numeric order)
3 should come before 3A (number and strings)
3A should come before 3A1 (numbers, strings, numbers)
My try:
My current code is sorting by numbers (condition 1), but ignores condition 2 and condition 3.
Therefore, my code gives me this order:
1, 2, 3A, 3, 3C, 3B, 4 <-- all 3's are not ordered, which is bad
The code I'm using (in functions.php):
add_action('pre_get_posts', function ($q) {
if (
!is_admin() // Target only front end queries
&& $q->is_main_query() // Target the main query only
&& ($q->is_search() || $q->is_post_type_archive('data-base'))
) {
$q->set('meta_key', 'custom_order');
$q->set('order', 'DESC');
$q->set('orderby', 'meta_value_num');
}
});

Answer 1

I found a neat solution!
$q->set(
'meta_query',
array(
'relation' => 'OR', //**** Use AND or OR as per your required Where Clause
'clause1' => array(
'key' => 'custom_order',
'compare' => 'EXISTS',
),
)
);
$q->set(
'orderby',
array(
'meta_value_num' => 'ASC', // this reorders by numbers
'meta_value' => 'ASC', // this reorders by strings after sorting numbers
)
);