| Data | DataChildren | Category
----------------------------------
| id | id | id
| name | data_id | name
| | category_id |
| | name |
数据模型:
public function data_children() {
return $this->hasMany(DataChildren::class, 'data_id', 'id');
}
DataChildren模型:
public function category() {
return $this->belongsTo(Category::class, 'category_id', 'id');
}
我想根据Data
id通过DataChildren
得到Category
的计数。我只是想从数据中获取类别记录,所以结果应该是这样的
name from category | Count of category for Data
-------------------------------------------------
Unpublished | 1
Published | 3
我试过使用这个,但返回null
Data::withCount(['category'=> function($query){return $query->groupBy('category_id');}])->find(1);
你需要使用多对多关系
类别模型:
public function datas()
{
return $this->belongsToMany(Data::class, 'data_childerens', 'category_id', 'data_id');
}
然后运行这个Query withCount:
Category::withCount('datas')->get();
Set Data Model:
public function categories()
{
return $this->belongsToMany(Category::class, 'data_childerens', 'data_id', 'data_id');
}
然后运行这个Query With and withCount:
Data::with('categories')->withCount('datas')->get();