↗️ 👋 😗 在Laravel中使用特征进行多态关系 ☕️ 👩‍👩‍👧‍👧 👩‍🌾

介绍

让我们谈谈在Laravel中特性以及多态关系的可能使用。

文章内容：

域说明

我们将开发一个系统，其中一些员工和某些团队可以加入该项目。主题领域的实质将是员工，团队和项目：一个由员工组成的团队，员工和团队可以附加到项目中。在团队和员工之间，存在多对多关系（假设员工可以参加不同的团队），项目与员工之间是多对多关系，团队与项目之间是多对多关系。为了进一步考虑，让我们省略团队与员工之间的沟通实施，而只关注团队和员工对项目的态度。

应用程式建立

Laravel应用程序使用application maker软件包非常容易构建。安装后，创建一个新应用程序适合一个命令：

laravel new system

可能的数据库结构

, : -, -, -.

, - - , (, 1 — , 2 — ).

- , — , .

, , , . :

php artisan make:model Employee -f //    
php artisan make:model Team -f //    
php artisan make:model Project -f //    
php artisan make:migration CreateEntitiesTables //     
php artisan make:model Attach -m //

App/, database/migrations/ database/factories/.

. , : , . — .

<?php

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

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

        Schema::create('teams', function (Blueprint $table) {
            $table->id();
            $table->string('name');
            $table->timestamps();
        });

        Schema::create('projects', function (Blueprint $table) {
            $table->id();
            $table->string('name');
            $table->timestamps();
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('employees');
        Schema::dropIfExists('teams');
        Schema::dropIfExists('projects');
    }
}

<?php

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

class CreateAttachesTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('attachments', function (Blueprint $table) {
            $table->id();
            $table->morphs('attachable');
            $table->unsignedInteger('project_id');
            $table->timestamps();

            $table->foreign('project_id')->references('id')->on('projects')
                ->onDelete('cascade');
        });
    }

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

, morphs().

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Employee extends Model
{
    protected $fillable = ['name'];
}

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Team extends Model
{
    protected $fillable = ['name'];
}

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\HasMany;
use Illuminate\Database\Eloquent\Relations\MorphToMany;

class Project extends Model
{
    protected $fillable = ['name'];

    /**
     * Relation for project attachments
     * @return HasMany
     */
    public function attachments()
    {
        return $this->hasMany(Attach::class);
    }

    /**
     * Relation for project employees
     * @return MorphToMany
     */
    public function employees()
    {
        return $this->morphedByMany(Employee::class, 'attachable', 'attachments');
    }

    /**
     * Relation for project teams
     * @return MorphToMany
     */
    public function teams()
    {
        return $this->morphedByMany(Team::class, 'attachable', 'attachments');
    }    
}

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Attach extends Model
{
    protected $table = 'attachments';
    protected $fillable = ['attachable_id', 'attachable_type', 'project_id'];
}

<?php

/** @var \Illuminate\Database\Eloquent\Factory $factory */

use Faker\Generator as Faker;

$factory->define(/* (//) */, function (Faker $faker) {
    return [
        'name' => $faker->colorName
    ];
});

, .

Laravel — morphedByMany(), — morphToMany(). , .

app/Traits : Attachable.php

<?php

namespace App\Traits;

use App\Project;
use Illuminate\Database\Eloquent\Relations\MorphToMany;

trait Attachable
{
    /**
     * Relation for entity attachments
     * @return MorphToMany
     */
    public function attachments()
    {
        return $this->morphToMany(Project::class, 'attachable', 'attachments');
    }
}

use.

...
    use Attachable;
...

, Laravel PHPUnit . :

php artisan make:test AttachableTest

tests/Feature/. RefreshDatabase.

检查项目方面的变体以及团队和员工方面的特征

<?php

namespace Tests\Feature;

use App\Team;
use App\Employee;
use App\Project;
use Illuminate\Foundation\Testing\RefreshDatabase;
use Tests\TestCase;

class OrderTest extends TestCase
{
    use RefreshDatabase;

    /** @test */
    public function polymorphic_relations_scheme(): void
    {
        // Given project
        $project = factory(Project::class)->create();
        // Given team
        $team = factory(Team::class)->create();
        // Given employee
        $employee = factory(Employee::class)->create();

        // When we add team and employee to project
        $project->teams()->save($team);
        $project->employees()->save($employee);

        // Then project should have two attachments
        $this->assertCount(2, $project->attachments);
        $this->assertCount(1, $project->teams);
        $this->assertCount(1, $project->employees);
        $this->assertEquals($team->id, $project->teams->first()->id);
        $this->assertEquals($employee->id, $project->employees->first()->id);
        // Team and employee should have attachment to project
        $this->assertCount(1, $team->attachments);
        $this->assertCount(1, $employee->attachments);
        $this->assertEquals($project->id, $team->attachments->first()->id);
        $this->assertEquals($project->id, $employee->attachments->first()->id);
    }
}

测试通过了！

特性允许您不要在模型类中复制通用的多态关系方法，如果您在许多表中具有相同的字段（例如，记录的作者），也可以使用它们-在这里您还可以使用连接方法来使特性。

我很高兴听到您在Laravel和PHP中使用特征的案例。

在Laravel中使用特征进行多态关系

介绍

域说明

应用程式建立

可能的数据库结构

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