如何获得Laravel的Belongsto伯爵？

Question

I want to get the count of the elements of materials count.

SubCategory:

public function materials(){
        return $this->hasMany('App\Material');
    }

Materials:

 public function subcategories(){
        $this->belongsTo('App\SubCategory','SubCategoria_id');
    }

I want to get the count of the elements that have the subcategory_id

'quantidade' => $subcategory->material->count()

I'm getting error in 1054 Unknown column 'material.subcategory_id'

Answer 1

Since you're using a custom foreign key, you need to specify it. So, change the relation to:

public function materials()
{
    return $this->hasMany('App\Material', 'SubCategoria_id');
}

And then use the proper relationship name:

$subcategory->materials()->count()