Laravel model relationships ดึงข้อมูล 10000+ record error 500

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Province extends Model
{
    /**
     * The table associated with the model.
     *
     * @var string
     */
	protected $table = 'provinces';

    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */
    protected $fillable = [
        'name'
    ];

    /**
     * The attributes that should be mutated to dates.
     *
     * @var array
     */
    protected $dates = ['created_at', 'updated_at'];

    /**
     * Get the districts for the province.
     */
    public function districts() {
        return $this->hasMany(District::class);
    }
}

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class District extends Model
{
    /**
     * The table associated with the model.
     *
     * @var string
     */
	protected $table = 'districts';

    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */
    protected $fillable = [
        'name'
    ];

    /**
     * The attributes that should be mutated to dates.
     *
     * @var array
     */
    protected $dates = ['created_at', 'updated_at'];

    /**
     * Get the province of the district.
     */
    public function province() {
        return $this->belongsTo(Province::class);
    }

<?php

use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreateProvincesTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('provinces', function (Blueprint $table) {
            $table->increments('id');
            $table->string('name');
            $table->timestamps();
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::drop('provinces');
    }
}

<?php

use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreateDistrictsTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('districts', function (Blueprint $table) {
            $table->increments('id');
            $table->string('name');
            $table->timestamps();
        });

		Schema::table('districts', function (Blueprint $table) {
            $table->integer('province_id')->unsigned()->after('name');
            $table->foreign('province_id')->references('id')
                ->on('provinces')->onDelete('cascade');
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
	    Schema::table('districts', function (Blueprint $table) {
            $table->dropForeign('districts_province_id_foreign');
        });

        Schema::drop('districts');
    }
}