How to synchronise child table data on hasMany relationship? - laravel

Question

I have 2 table products and variants, with a hasMany relationship, the structure is below :
Product Model :
public function variants()
{
return $this->hasMany(Variant::class);
}
Variant Model :
public function product()
{
return $this->belongsTo(Product::class);
}
Product Table :
| id name image manufacturer
| 1 T-Shirt t-s.jpg docomo
| 2 Short Skirt s-skirt.jpg docomo
Variant Table :
| id product_id name price sku quantity
| 1 1 S 30 ts-s 100
| 2 1 M 32 ts-m 100
| 3 1 XL 35 ts-xl 100
| 4 2 S 23 sk-s 100
| 5 2 M 25 sk-m 100
| 6 2 XL 28 sk-xl 100
I can save data on Variant model (child table) from Product model as :
public function store(Request $request)
{
$q = new Product;
$q->name = $request->name;
$q->save();
// Below child table
$q->variants()->createMany($request->variant);
}
I can store data, but the problem is that, how can I update child table? [It can be create, update or delete]
I tried with sync() method, but didn't work. Its for manyToMany relationship.
public function update(Request $request)
{
$q = Product::findOrFail($request->id);
$q->name = $request->name;
$q->save();
// Below child table update
// $q->variants()->sync($request->variant); // not worked
}
sync() works in manyToMany relationship. I need the same for hasMany relationship.
How can I do that?

Answer 1

Unfortunately there is no sync method for hasMany relations. It's pretty simple to do it by yourself. You can simple delete the rows and insert them all again.
public function update(Request $request, Product $product)
{
$product->update(['name' => $request->name]);
// Below child table update
$product->variants()->delete();
$product->variants()->sync($request->variant);
}