Laravel中实现多类型附件关联：非多态模型的统一管理

<?php

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

class CreateAttachmentsTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('attachments', function (Blueprint $table) {
            $table->id();
            $table->foreignId('page_id')->constrained()->onDelete('cascade'); // 关联到 pages 表
            $table->string('file'); // 附件文件路径或名称
            $table->string('type'); // 附件类型，例如 'image', 'video'
            $table->timestamps();
        });
    }

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

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class Attachment extends Model
{
    use HasFactory;

    protected $fillable = [
        'file',
        'type',
        'page_id', // 允许批量赋值 page_id
    ];

    /**
     * 获取拥有此附件的页面。
     */
    public function page()
    {
        return $this->belongsTo(Page::class);
    }

    /**
     * 辅助方法：判断附件是否为图片
     */
    public function isImage(): bool
    {
        return $this->type === 'image';
    }

    /**
     * 辅助方法：判断附件是否为视频
     */
    public function isVideo(): bool
    {
        return $this->type === 'video';
    }
}

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class Page extends Model
{
    use HasFactory;

    protected $fillable = [
        'slug',
        // ... 其他页面字段
    ];

    /**
     * 获取页面所有的附件。
     */
    public function attachments()
    {
        return $this->hasMany(Attachment::class);
    }
}

use App\Models\Page;

$page = Page::find(1); // 假设存在 ID 为 1 的页面

if ($page) {
    echo "页面: " . $page->slug . "\n";
    foreach ($page->attachments as $attachment) {
        echo "  - 附件文件: " . $attachment->file . " (类型: " . $attachment->type . ")\n";
        // 根据类型进行不同处理
        if ($attachment->isImage()) {
            echo "    这是一个图片附件。\n";
        } elseif ($attachment->isVideo()) {
            echo "    这是一个视频附件。\n";
        }
    }
} else {
    echo "页面未找到。\n";
}

use App\Models\Page;
use App\Models\Attachment;

$page = Page::find(1); // 假设存在 ID 为 1 的页面

if ($page) {
    // 方式一：单独保存一个附件
    $imageAttachment = new Attachment([
        'file' => 'images/page-1-photo-1.jpg',
        'type' => 'image',
    ]);
    $page->attachments()->save($imageAttachment);
    echo "图片附件已保存。\n";

    // 方式二：批量保存多个附件
    $videoAttachment = new Attachment([
        'file' => 'videos/page-1-clip-1.mp4',
        'type' => 'video',
    ]);
    $anotherImageAttachment = new Attachment([
        'file' => 'images/page-1-photo-2.png',
        'type' => 'image',
    ]);

    $page->attachments()->saveMany([$videoAttachment, $anotherImageAttachment]);
    echo "视频和另一张图片附件已批量保存。\n";

    // 方式三：使用 createMany 方法创建并关联
    $page->attachments()->createMany([
        ['file' => 'images/page-1-photo-3.gif', 'type' => 'image'],
        ['file' => 'videos/page-1-clip-2.mov', 'type' => 'video'],
    ]);
    echo "更多附件已通过 createMany 保存。\n";

} else {
    echo "页面未找到，无法添加附件。\n";
}