displaying an array but it return empty - laravel

Question

Good day, i have a laravel 5.8 project and i'm having a little problem
i have this code
public function doctor_details($doctor_id){
$doctor = DB::table('doctors')->select('specification')->where('doctor_id', $doctor_id)->get>first();
$specs_data = explode(',', $doctor_specs);
$specs_array = [];
foreach ($specs_data as $doctor_spec) {
$doctor_spec_result = DB::table('specializations')->where { return explode('speciality_id'',', $doctor_spec)->get();
foreach ($doctor_spec_result as $doctor_spec_res) {
$specs_array[] = $doctor_spec_res->speciality_name;
}
}
return view ('doctor_details', compact('doctor', 'specs_array'));
}
now if i do dd($doctor_spec_result); the result is
as you can see i'm getting an empty array but if i do dd($specs_data); the result is
as you can see there's definitely a data but i can't make it work
this is my blade
<div class="row">
<div class="col-lg-12">
<h3>{{ $doctor->doctor_name }}</h3>
</div>
<div class="col-lg-12">
#foreach( $specs_array as $spec_output )
<p>{!! $spec_output !!}</p>
#endforeach
</div>
</div>

Answer 1

I think you are trying to get an list only containing the values of the specification field for the particular rows queried, so that you can then get the specialty_names. You can use the pluck method on the builder to do this for you. If a search by doctor_id could return more than one result:
$doctor_specs = DB::table('doctors')
->where('doctor_id', $doctor_id)
->pluck('specification')
->transform(function ($item) { return explode(',', $item); })
->flatten();
$specs_array = DB::table('specializations')
// use whereIn to find all the rows by 'specialty_id'
->whereIn('speciality_id', $doctor_specs)
->pluck('specialty_name')
->toArray();
return view ('doctor_details', compact('doctor', 'specs_array'));
Laravel 6.x Docs - Database - Query Builder - Retrieving Results pluck
Laravel 6.x Docs - Collections - Methods - transform
Laravel 6.x Docs - Collections - Methods - flatten
Update:
Though since doctor_id is a key there will only be one, we can remove the collection methods and deal with this simpler:
$doctor_specs = explode(
',',
DB::table('doctors')->where('doctor_id', $doctor_id)
->value('specification')
);
Ideally:
Or if $doctor was retrieved with all columns from the doctors table, including specification:
$doctor_specs = explode(',', $doctor->specification);

Answer 2

You can simplify your code using join
$doctor_spec_result = DB::table('doctors')
->select('specializations.speciality_name')
->join('specializations','specializations.speciality_id','doctors.specification')
->where('doctors.doctor_id', $doctor_id)
->get();
return view ('doctor_details', compact('doctor', 'doctor_spec_result '));

Answer 3

Change in this line.
$doctor_spec_result = DB::table('specializations')->where('speciality_id', $doctor_spec)->get();
you are checking the worng attribute. As you are getting specification in 0 index.
speciality_id to specification