如何仅检索 Laravel 中未从数据库中删除的记录？

Question

I have recommends table that has product_id , user_id and deleted_at columns and I want to display the most viewed products in the view and it works fine but the problems is when user deletes the product I get an error trying to get property of non object and the column deleted_at in recommends table still showing null even if the product is deleted. How can I make the product disappear in recommends table after the product has been deleted and the view should display only the products which are not deleted?

Controller

  $recommends = Recommends::with('product')
    ->select('product_id', DB::raw('COUNT(*) AS total'))
    ->whereNotNull('product_id')
    ->groupBy('product_id')
    ->orderby('total', 'DESC')
    ->take(12)
    ->get();

Recommends.php

 <?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Recommends extends Model
{
public function product()
{
    return $this->belongsTo('App\Product','product_id')
}
}

Product.php

 public function recommends()
 {
    return $this->hasMany('App\Recommends','product_id');
 }

Answer 1

Try with wherehas() it will check that product exist or not:

$recommends = Recommends::with('product')
    ->select('product_id', DB::raw('COUNT(*) AS total'))
    ->whereNotNull('product_id')
    ->wherehas('product')
    ->groupBy('product_id')
    ->orderby('total', 'DESC')
    ->take(12)
    ->get();

And also on delete product remove all recommendations for that product.

Change in Product model,

protected static function boot() {
   parent::boot();

   static::deleting(function($product) {
     $product->recommends()->delete();
   });
}

Answer 2

When soft deleting a model, it is not actually removed from your database. Instead, a deleted_at timestamp is set on the record. To enable soft deletes for a model, apply the SoftDeletes to the model:

use Illuminate\Database\Eloquent\SoftDeletes;

class Product extends Model {

    use SoftDeletes;

    protected $dates = ['deleted_at'];

}

Now, when you call the delete method on the model, the deleted_at column will be set to the current timestamp. When querying a model that uses soft deletes, the "deleted" models will not be included in query results.

Please check more info of soft delete

After soft delete if you run this query the product will not come which is soft-deleted.

 $recommends = Recommends::with('product')