Why don't all required fields get validated?

Question

ASP.NET

There is an entity:
public class Products
{
public int Id { get; set; }
[Required(AllowEmptyStrings = false)]
public string Name { get; set; }
[Required(AllowEmptyStrings = false)]
public string Description { get; set; }
[Required]
[DataType(DataType.DateTime)]
public DateTime Created_at { get; set; }
[Required]
public int In_stock { get; set; }
[Required]
public decimal Price { get; set; }
[Required]
public int External_id { get; set; }
}
POST request, I pass json in the body
In the controller public ActionResult CreateProduct(Products product)
I check
if (ModelState.IsValid)
If there is no Name or description field, then an error is returned.
If name, description are present, but others are not, then everything is OK. Why is that?
I assume that when a product is created, then the fields (which are not string) are filled with zeros and supposedly this is ok. If so, how to fix it?

Answer 1

Make fields nullable or implement IValidatableObject.