laravel collection 个 collection 计数

Question

我正在尝试从嵌套关系中获取记录数。我想获得属于田地和农场的绵羊总数，但不知道如何在不遍历 @foreach 循环和更新变量的情况下完成此操作。 Eloquent 非常干净所以我觉得有一个简单优雅的解决方案。

谢谢

我有4个模型，farm, field, shepherd, sheep 它们是hasMay关系

class Farm extends Model {

    protected $fillable = ['name, user_id'];

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

    public function fieldCount() {
        return $this->fields->count();
    }

}

class Field extends Model {

    protected $fillable = ['name, farm_id, user_id'];

    public function farm() {
        return $this->belongsTo('App\farm');
    }

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

    public function group() {
        return $this->belongsTo('App\Group');
    }

    public function shepherdCount() {
        return $this->shepherds->count();
    }

    public function shepherdSheepCount() {
        return $this->
    }

}


class Shepherd extends Model {

    protected $fillable = ['name, field_id, user_id'];

    public function field() {
        return $this->belongsTo('App\Field');
    }

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

    public function sheepCount() {
        return $this->sheep->count();
    }

}

class Sheep extends Model {

    protected $fillable = ['name, shepherd_id, user_id'];

    public function shepherd() {
        return $this->belongsTo('App\Shepherd');
    }

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

}


#CONTROLLER METHOD
public function test()
{
    $Farms = Farm::with('fields',
                        'fields.shepherds',
                        'fields.shepherds.sheep')->get();
    return view('test')->with('farms', $Farms);
}



#VIEW
                    <ul>
                        @foreach ($farms as $farm)
                            <li>{{$farm->name}} Farm - {{$farm->fieldCount()}}</li>

                            <ul >
                            @foreach ($farm->fields as $field)
                                <li>{{$field->name}} Field - {{ $field->shepherdCount()}}</li>
                                    <ul>
                                        @foreach ($field->shepherds as $shepherd)
                                            <li>
                                            Shepherd  {{ $shepherd->name }} has 
                                            {{ $shepherd->sheepCount() }} sheep
                                            </li>   
                                        @endforeach
                                    </ul>     
                            @endforeach
                            </ul>   
                        @endforeach  
                    </ul>

查看结果

Idaho Farm - 2
    West Mervinland Field - 3
        Shepherd Fermin has 61 sheep
        Shepherd Clement has 54 sheep
        Shepherd Ned has 57 sheep
    North Mariellebury Field - 2
        Shepherd Chadrick has 53 sheep
        Shepherd Jackson has 61 sheep
Washington Farm - 0
California Farm - 4
    Andersonport Field - 0
    South Carmenborough Field - 3
        Shepherd Alfonzo has 49 sheep
        Shepherd Boris has 59 sheep
        Shepherd Omari has 53 sheep
    West Archibaldhaven Field - 4
        Shepherd Darrin has 64 sheep
        Shepherd Davion has 53 sheep
        Shepherd Miller has 51 sheep
        Shepherd Kristoffer has 59 sheep
    Cassinmouth Field - 2
        Shepherd Paxton has 50 sheep
        Shepherd Hayley has 56 sheep

Answer 1

这是应该的

class Sheep extends Model {

    //specify the table explicitly otherwise laravel will assume sheeps
    protected $table = 'sheep';

    //sheep belongs to a field
    public function field(){
        return $this->belongsTo('App\Field', 'foreign_key', 'primary_key');
    }

}

class Field extends Model {


    //field belongs to a farm
    public function farm() {
        return $this->belongsTo('App\Farm', 'foreign_key', 'primary_key');
    }

    //field has many sheep
    public function sheep() {
        return $this->hasMany('App\Sheep', 'foreign_key', 'primary_key');
    }

}

class Farm extends Model {

    //farm has many fields
    public function fields() {
        return $this->hasMany('App\Field');
    }

}

得到这样的结果

$farm->fields // would always return collection since 1-many relation so you //have to loop through it 
    foreach($fields as $field){
        $field->sheep;//this will also return collection
}

你可以在这些上应用所有的集合方法，可能 count() 也是一种方法，请参阅 laravel 集合的文档以获取更多信息。

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查看结果