如何在 laravel 中的 foreach 循环后部署分页答案

【问题标题】：How can i deploy pagination after foreach loop in laravel如何在 laravel 中的 foreach 循环后部署分页
【发布时间】：2021-08-30 16:28:57
【问题描述】：

我正在尝试在搜索结果中创建分页。我的存储库中有一个查询，例如：

public function getFilteredVehicles($id,$pax,$categories,$search_type,$from_date,$to_date)
{
    $vehicles = Vehicle::whereHas('destinations', function($q) use($id){
        $q->where('destination_id',$id)
            ->where('active',1);
        })
        ->paginate(1);

    if($search_type == 'disposal' || $search_type == 'pnd')
    {
        $vehicles = $vehicles->where('registered_location',$id);
    }

    if($categories)
    {
        $vehicles = $vehicles->where('vehicle_categoryid',$categories);
    }

    return $vehicles;
}

返回的结果需要再次循环处理，如：

public function calculateLocationAmount($vehicles,$fdate,$tdate,$destination_id)
{
    $datetime1 = new DateTime($fdate);
    $datetime2 = new DateTime($tdate);

    $interval = $datetime1->diff($datetime2);
    $days = $interval->format('%a');
    $days = $days+1;
    $nights = $days-1;

    foreach ($vehicles as $key => $vehicle) {
        # code...
        $perday_rate = $vehicle->destinations->where('id',$destination_id)->first()->pivot->day_rate;
        $pernight_rate = $vehicle->destinations->where('id',$destination_id)->first()->pivot->night_rate;

        $day_rate = $perday_rate * $days;
        $night_rate = $pernight_rate * $nights;
        $total_amount = $day_rate + $night_rate;
        $vehicle['total_amount'] = $total_amount;
        $vehicle['availability'] = 'true';

        if($vehicle->whereHas('unavailability', function($q) use($fdate,$tdate){
                            $q->whereRaw("? BETWEEN `from_date` AND `to_date`", [$fdate])
                                ->orwhereRaw("? BETWEEN `from_date` AND `to_date`", [$tdate]);
                        })->count()>0){
            $vehicle['availability'] = 'false';
        }
    }
    
    return $vehicles;
}

这个最终结果需要分页。我该怎么做？

使用 foreach 会将值更改为集合，因为哪些链接不起作用。如果我不执行paginate() 或get()，则不会执行 for 循环。

请帮忙。

【问题讨论】：

标签： php mysql laravel foreach pagination

【解决方案1】：

您可以像以前一样对初始查询进行分页，然后像常规集合一样循环分页对象或使用$pagination->items()

您还应该在初始查询中使用嵌套的 with('relation') 来停止 N+1 查询 https://laravel.com/docs/8.x/eloquent-relationships#constraining-eager-loads

【讨论】：

循环后自动变为collection，blade报错。