nang cap san sang import

app/Models/Product.php

@@ -5,6 +5,7 @@ namespace App\Models;
 use Illuminate\Database\Eloquent\Attributes\Fillable;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\BelongsToMany;
+use Illuminate\Database\Eloquent\Relations\HasMany;
 
 #[Fillable(['name', 'description', 'status'])]
 class Product extends Model
@@ -15,4 +16,19 @@ class Product extends Model
             ->withPivot('purchase_date')
             ->withTimestamps();
     }
+
+    public function contracts(): HasMany
+    {
+        return $this->hasMany(Contract::class);
+    }
+
+    public function handovers(): HasMany
+    {
+        return $this->hasMany(Handover::class);
+    }
+
+    public function productServices(): HasMany
+    {
+        return $this->hasMany(ProductService::class);
+    }
 }