DataTables ajax fails on 1-n relation

[mpixelz]

Hi,
i have three relations (country, state, city) so 1 country with many states, 1 state with many cities..
when i have more than 1 belongsTo in my city model it does not fetch the connected country.. without ajax it times out max_execution time error.. but when i enable
$this->crud->enableAjaxTable();
it gives me:
DataTables warning: table id=crudTable - Ajax error. For more information about this error, please see http://datatables.net/tn/7

here is my CityCrudController:

<?php namespace App\Http\Controllers\Admin;

use Backpack\CRUD\app\Http\Controllers\CrudController;

// VALIDATION: change the requests to match your own file names if you need form validation
use App\Http\Requests\CityRequest as StoreRequest;
use App\Http\Requests\CityRequest as UpdateRequest;

class CityCrudController extends CrudController {

    public function __construct() {
        parent::__construct();
        $this->crud->enableAjaxTable(); 

        $this->crud->setModel("App\Models\City");
        $this->crud->setRoute("admin/cities");
        $this->crud->setEntityNameStrings('City', 'Cities');

        $this->crud->addColumns([
                [
                    'name'  => 'name',
                    'label' => 'Name',
                    'type'  => 'text',
                ],
                [
                   // 1-n relationship
                   'label' => "State", // Table column heading
                   'type' => "select",
                   'name' => 'state_id', // the method that defines the relationship in your Model
                   'entity' => 'state', // the method that defines the relationship in your Model
                   'attribute' => "name", // foreign key attribute that is shown to user
                   'model' => "App\Models\State", // foreign key model
                ],
                [
                   // 1-n relationship
                   'label' => "Country", // Table column heading
                   'type' => "select",
                   'name' => 'country_id', // the method that defines the relationship in your Model
                   'entity' => 'country', // the method that defines the relationship in your Model
                   'attribute' => "name", // foreign key attribute that is shown to user
                   'model' => "App\Models\Country", // foreign key model
                ]
                              ]);
        $this->crud->addFields([
                [
                    'name'  => 'name',
                    'label' => 'Name',
                    'type'  => 'text',
                ],
                [
                   // 1-n relationship
                   'label' => "State", // Table column heading
                   'type' => "select",
                   'name' => 'state_id', // the method that defines the relationship in your Model
                   'entity' => 'state', // the method that defines the relationship in your Model
                   'attribute' => "name", // foreign key attribute that is shown to user
                   'model' => "App\Models\State", // foreign key model
                ],
                [
                   // 1-n relationship
                   'label' => "Country", // Table column heading
                   'type' => "select",
                   'name' => 'country_id', // the method that defines the relationship in your Model
                   'entity' => 'country', // the method that defines the relationship in your Model
                   'attribute' => "name", // foreign key attribute that is shown to user
                   'model' => "App\Models\Country", // foreign key model
                ]
                              ]);
    }

    public function store(StoreRequest $request)
    {
        return parent::storeCrud();
    }

    public function update(UpdateRequest $request)
    {
        return parent::updateCrud();
    }
}

here is my model City.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;
use Backpack\CRUD\CrudTrait;

class City extends Model
{

    use CrudTrait;

    protected $table = 'citys';
    protected $primaryKey = 'id';
    // public $timestamps = false;
    // protected $guarded = ['id'];
    // protected $fillable = [];
    // protected $hidden = [];
    // protected $dates = [];

    public function state()
    {
        return $this->belongsTo('App\Models\State');
    }
    public function country()
    {
        return $this->belongsTo('App\Models\Country');
    }
}

how can i connect the country to the city model so it will display connected country through state relation?

[mpixelz]

Ive already tried the method here: #87 (comment)

P.S i just did composer update and the crud and base were updated along with laravel framework update but the issue still persists.

[OwenMelbz]

Just to clarify something,

You've got

                [
                   // 1-n relationship
                   'label' => "State", // Table column heading
                   'type' => "select",
                   'name' => 'state_id', // the method that defines the relationship in your Model
                   'entity' => 'state', // the method that defines the relationship in your Model
                   'attribute' => "name", // foreign key attribute that is shown to user
                   'model' => "App\Models\State", // foreign key model
                ],

However, you only posted your Country model - I think yu should have a relationship inside your State model called "country" with another belongsTo in it

// State.php
 public function country()
    {
        return $this->belongsTo('App\Models\Country');
    }

then within your original addFields call change the 'name' => 'state_id', and 'entity' => 'state' to contain country instead of state

I believe the way it works is, It looks for the method defined within name/entity, inside the model you pass in. As you're passing in the State model, its looking for state in it currently, which wouldnt make sense. So you need to say "look at the country, within the state" instead.

[tabacitu]

Hi @mpixelz ,

I completely agree with @OwenMelbz - the 1-n column (select) works with 1-n relationships only. The relationship between your City and Country isn't 1-n. It's more like 1-n-n :-)

I have only one thing to add to @OwenMelbz 's response, only if his solution doesn't work for you: I think you might be able to create a fake 1-n relationship between City and Country using Laravel's hasManyThrough(). However, I haven't tried that myself in Backpack.

Cheers!

PS. If you end up trying hasManyThrough(), I'm very eager to find out if it worked :-)

[OwenMelbz]

@mpixelz just doing the cleaning, so closing the issue, feel free to re-open if you still need help!

[mpixelz]

reopening this as the issue still persists.
here is the scenario.. User have PersonalDetail table where all the personal information is stored.
User model have:

public function PersonalDetail()
    {
        return $this->hasOne('App\Models\PersonalDetail' , 'user_id');
    }

in my crud.. when i use this model on select for 1-n relation:

$this->crud->addColumn([
               // 1-n relationship
               'label' => "Mobile", // Table column heading
               'type' => "select",
               'name' => 'user_id', // the column that contains the ID of that connected entity;
               'entity' => 'PersonalDetail', // the method that defines the relationship in your Model
               'attribute' => "mobileno", // foreign key attribute that is shown to user
               'model' => "App\Models\PersonalDetail", // foreign key model
            ]);

now when i enable ajax tables i get the error.. but if i remove this column it works fine.