php - laravel 查询多对多

Question

我有 2 个模型，Service 和 Category。它们与这样的多对多关系相关:

Service.php

public function categories()
{
   return $this->belongsToMany('App\Category')->withTimestamps();
}

Category.php

public function services()
{
   return $this->belongsToMany('App\Service')->withTimestamps();
}

当然，它们由数据透视表连接:

category_service

  - category_id
  - service_id
  - created_at
  - updated_at

我想使用本地范围根据类别 ID 过滤服务结果。我做了以下事情:

Service.php

public function scopeFilter($query, $category_ids)
{
    $services = Service::whereHas('categories', function (Builder $query) use ($category_ids) {
        $query->whereIn('category_id', $category_ids)->get();
    });

    return $services;
}

但是我遇到了一个Column not found错误，特别是:

Column not found: 1054 Unknown column 'services.id' in 'where clause' (SQL: select * from `categories` inner join `category_service` on `categories`.`id` = `category_service`.`category_id` where `services`.`id` = `category_service`.`service_id` and `category_id` in (1, 2))

1 和 2 是我传递的类别 ID。

我根据找到的答案编写了函数 here和 here .

有什么建议吗？

Answer 1

您的错误消息显示您的查询以 categories 开头并且没有加入 services。

所以将 ->get() 放在闭包之外。

public function scopeFilter($query, $category_ids)
{
    $services = Service::whereHas('categories', function (Builder $query) use ($category_ids) {
        $query->whereIn('category_id', $category_ids);
    })->get();

    return $services;
}