Updated validation logics for resource, importer, exporter, create files and Added columns in model file

app/Models/ProductionOrder.php

@@ -8,6 +8,7 @@ use Illuminate\Database\Eloquent\SoftDeletes;
 class ProductionOrder extends Model
 {
     use SoftDeletes;
+
     protected $fillable = [
         'plant_id',
         'item_id',
@@ -17,6 +18,10 @@ class ProductionOrder extends Model
         'production_order',
         'from_serial_number',
         'to_serial_number',
+        'created_at',
+        'created_by',
+        'updated_at',
+        'updated_by',
     ];
 
     public function plant()