Laravel Eloquent Advance Querying - laravel

Question

I have 5 different tables as projects, systems, attachments, tasks, users on Laravel I haven't assign a relationship for each table what I am trying to do is linking each table using ID.
$objFetch = Task::addSelect(
[
'project_id' => Project::select('title')->whereColumn('project_id', 'projects.id'),
'tester_id' => User::select('name')->whereColumn('tester_id', 'users.id'),
'system_id' => System::select('name')->whereColumn('system_id', 'systems.id'),
'assigned_id' => User::select('name')->whereColumn('assigned_id', 'users.id'),
],
)->paginate(20);
This return the expected output as
{
"id": 1,
"document_auto_id": 101,
"document_type": null,
"document_name": "Tasks",
"file_name": "Task_394_1622175671_195.png",
"file_extention": "png",
"file_size": "105383",
"note": null,
"created_at": "2021-05-28T04:21:11.000000Z",
"updated_at": "2021-05-28T04:21:11.000000Z"
},
Question is there any solutions to get the attachments for each tasks?
Laravel Eloquent answer is highly appreciated instead of Query building

Answer 1

DB tables are often related to one another. therefore we can use table ID to get the output. the error occurs because I have not defined it on the Model. THE PROBLEM WAS SOLVED AS I DO FOLLOWING STEPS
MODEL
class Task extends Model
{
use HasFactory;
protected $fillable = [
'title',
'priority',
'project_id',
'system_id',
'tester_id',
'assigned_id',
'description',
'status',
];
protected $casts = [
'attachments' => 'array',
];
public function Attachment()
{
return $this->hasMany(Attachment::class, 'document_auto_id');
}
public function Project()
{
return $this->hasOne(Project::class, 'id', 'project_id');
}
public function System()
{
return $this->hasOne(System::class, 'id', 'system_id');
}
public function assignedTo()
{
return $this->hasOne(User::class, 'id','assigned_id');
}
public function testerTo()
{
return $this->hasOne(User::class, 'id','tester_id');
}
}
FETCHING DATA WITH RELEVANT TABLES
$objFetch1 = Task::with(
'testerTo',
'assignedTo',
'System',
'Project',
'Attachment'
)->get();