同时从多个帖子中获取所有标签

Question

我需要创建一个查询，从帖子数组中获取所有标签。在标签和帖子之间的多对多多态关系中

标签模型

class Tag extends Model
{
    use HasFactory;
    protected $guarded = ['id'];
    //
    public function posts()
    {
        return $this->morphedByMany(Post::class, 'taggable');
    }
}

后模型

类 Post 扩展模型 { 使用 HasFactory;

protected $guarded = ['id'];

public function tags()
{
    return $this->morphToMany(Tag::class, 'taggable');
}

}

标签迁移

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

可标记迁移

public function up()
    {
        Schema::create('taggables', function (Blueprint $table) {
            $table->id();
            $table->bigInteger('tag_id')->unsigned();
            $table->morphs('taggable');

            $table->foreign('tag_id')->references('id')->on('tags')
                ->onDelete('cascade')
                ->onUpdate('cascade');
        });
    }

迁移后

Schema::create('posts', function (Blueprint $table) {
            $table->id();
            $table->string('title');
            $table->text('description');
            // 1 borrador, 2 revision, 3 publicado, 4 caducado
            $table->enum('status', [Post::BORRADOR, Post::REVISION, Post::PUBLICADO, Post::CADUCADO]);
            // Para diferenciar entre publicaciones del Sistema (Admin = 1) o de usuarios normales (USERS = 2)
            $table->enum('type', [Post::ADMIN, Post::USERS]);
            $table->boolean('atemporal');
            $table->string('slug')->unique();

            $table->unsignedBigInteger('user_id')->nullable();
            $table->unsignedBigInteger('survey_id')->nullable();

            $table->foreign('user_id')->references('id')->on('users')->onDelete('set null');
            $table->foreign('survey_id')->references('id')->on('surveys');


            $table->timestamps();
        });

类别迁移

Schema::create('categories', function (Blueprint $table) {
            $table->id();

            $table->string('name');
            $table->unsignedBigInteger('parent_id')->nullable();
            $table->string('slug');

            $table->foreign('parent_id')->references('id')->on('categories')->onDelete('cascade');
            $table->timestamps();
        });

数据透视表 CATEGORY_POST

Schema::create('category_post', function (Blueprint $table) {
            $table->id();

            $table->unsignedBigInteger('category_id');
            $table->unsignedBigInteger('post_id');

            $table->foreign('category_id')->references('id')->on('categories')->onDelete('cascade');
            $table->foreign('post_id')->references('id')->on('posts')->onDelete('cascade');

            $table->timestamps();
        });

关系帖子

public function categories()
    {
        return $this->belongsToMany(Category::class);
    }

关系类别

public function posts()
     {
         return $this->belongsToMany(Post::class);
     }

我已经尝试过了，但我无法让它工作

    $posts = Post::whereHas('categories', function($query) {
                    $query->whereIn('category_id', [$this->categoriaTags]);
                })->get(); 
// Here I get the list of posts from which I want to get their tags, this is OK.


//But then I can't get the right query to get the tags.
    $tags = Tag::whereHasMorph('posts', function($query) use($posts){
                    $query->where('tag_id', $posts);
                })->get();

有什么建议吗？谢谢

Answer 1

您很接近，但是您查询了错误的列，并且使用了错误的构建器方法。你想要：

    $tags = Tag::whereHasMorph('posts', function ($query) use ($posts) {
        $query->whereIn('id', $posts->pluck('id'));
    })->get();