groupBy only gets the first id - php

Question

I have a many to many relationship between departments and users my pivot table is department_user. I wanted to select all the department_name depending of the user's department using groupBy method to merge all the department_name into one. See below my statement.
$departmentRecipient = DB::table('users')->select('departments.department_name', 'users.id')
->join('department_user', 'users.id', '=', 'department_user.user_id')
->join('departments', 'department_user.department_id', '=', 'departments.id')
->groupBy('departments.department_name')
->get();
Result using die and dump.
As you can see here I have an id of 4 under "Department of Engineering". My main problem is it doesn't fetch all the id under "Department of Engineering". But in my SQL I have id of 5 not only 4. How can I solve this problem? Any help would greatly appreciated. Please see result below.
Output:
This is the output of my list. I wanted to get all the users id belongs to the specific option for the user. But if I choose "Department of Engineering" it only gets the id of 4 not 5. I wanted to get 4 and 5 once.
Controlller:
public function getDocuments()
{
$departmentRecipient = DB::table('departments')->get();
return view ('document.create')->with('departmentRecipient', $departmentRecipient);
}
public function postDocuments(Request $request)
{
$this->validate($request,
[
'title' => 'required|regex:/(^[A-Za-z0-9 ]+$)+/|max:255',
'content' => 'required',
'category' => 'required',
'recipient' => 'required',
]);
$document = new Document();
//Request in the form
$document->title = $request->title;
$document->content = $request->content;
$document->category_id = $request->category;
$document->save();
$user = Auth::user();
foreach($request->recipient as $recipientId)
{
$document->sentToUsers()->sync([ $recipientId => ['sender_id' => $user->id]],false );
}
}
Model
User
public function departments()
{
return $this->belongsToMany('App\Models\Department', 'department_user');
}
Department
public function users()
{
return $this->belongsToMany('\App\Models\User', 'department_user');
}
View
<div class = "form-group">
<label for = "recipient" class = "control-label">Recipient:</label>
<select name = "recipient[]" multiple class = "form-control select2-multi" id = "myUserList">
#foreach ($departmentRecipient as $list)
<option value = "{{ $list->id }}">{{ $list->department_name }}</option>
#endforeach
</select>
</div>

Answer 1

From your given code it seems you are not using Eloquent ORM, you are doing it using Query Builder.
If you don't have a performance concern right now you can do it using separate queries. Like-
$departmentRecipient = DB::table('departments')->all();
foreach($departmentRecipient as $department){
$department->users = DB::table('department_user')->where('department_id',$department->id)->pluck('user_id');
}
But the better way is to use the eloquent with relationships. Define the many to many relationship in your eloquent model of Users and Departments (assuming you have eloquent model for them). You will find details about eloquent relationships at laravel documentation.
Update:
From the update of your post it is actually pretty easy to do what you want. If your Request contains the selected department id then you can do the following:
public function postDocuments(Request $request)
{
$document = new Document();
$document->title = $request->title;
$document->content = $request->content;
$document->category_id = $request->category;
$document->save();
//get the users list of the selected department id
$selected_department = $request->department_id; //this must be included in your POST data
$users = DB::table('department_user')->where('department_id',$selected_department)->pluck('user_id');
//now you have the list of the users id
foreach($users as $user){
// do what you need here
}
}
Update 2:
Following controller code might work for you.
Controller:
public function getDocuments()
{
// I am suggesting here to change the '$departmentRecipient' to '$departmentlist', as it is more meaningful. Also in your view
$departmentlist = DB::table('departments')->get();
return view ('document.create')->with('departmentlist', $departmentlist);
}
public function postDocuments(Request $request)
{
//same as you have till the $document->save()
....
....
//then do this
$recipients = array();
$departments = $request->recipient;
foreach($departments as $department){
$users = DB::table('department_user')->where('department_id',$department)->pluck('user_id');
$recipients = array_merge($recipients, $users);
}
//now you have a complete list of the users from selected departments
//Do as you intend to like this
$user = Auth::user();
foreach($recipients as $recipientId)
{
$document->sentToUsers()->sync([ $recipientId => ['sender_id' => $user->id]],false );
}
}