Using whereRelation with a subquery - laravel

Question

I have wrote a zip_code query that I am wanting to add to another query. The problem is I am not exactly sure how to combine these via whereRelation().
$zip_code = ZipCode::where('office', '=', function ($query) {
$query->selectRaw('office')->from('zip_codes')->where('zip_code', session()->get('zip_code'));
})->get();
$appointment = Appointment::with('customer', 'blocks', 'status', 'services.service')->whereRelation('customer', 'zip_code', $zip_code)->get();
The output of $appointment is:
select * from appointments where exists (select * from customers where appointments.customer_id = customers.id and zip_code = {"id":1,"zip_code":00000,"city":"City","office":"LOCATION"})
$zip_code is returning this query. I am just wanting those results to be called in the whereRelation() so all the zip_codes for that office are returned:
SELECT * FROM zip_codes
where office = (
select office
from zip_codes
where zip_code = '00000'
)

Answer 1

You can pluck the zip_code values from the $zip_code collection like so.
$zip_code = ZipCode::select('zip_code')
->where(
'office',
function($query) {
$query->select('office')
->from('zip_codes')
->where(
'zip_code',
session()->get('zip_code')
);
}
)->get();
$zip_code = $zip_code->pluck('zip_code')->all();
Then use that in the next query for filtering the relation.
$appointment = Appointment::with('customer', 'blocks', 'status', 'services.service')
->whereRelation(
'customer',
function($query) {
$query->whereIn('zip_code', $zip_code);
}
)->get();
Otherwise, you could query for the office with the given zip code, carry out a join of the customer and the zip codes table then filter out customers with zip codes pertaining to the office.
$offices = ZipCode::select('office')
->where('zip_code', session()->get('zip_code'))
->get();
$offices = $offices->pluck('office')->all();
$appointment = Appointment::with(
'customer',
'blocks',
'status',
'services.service'
)->whereHas('customer', function ($query) {
$query->join('zip_codes', function ($join) {
$join->on('zip_codes.zip_code', 'customers.zip_code');
$join->whereIn('zip_codes.office', $office);
});
});