To simplify the problem, in C# I have a model like this

public class Person
{
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    [Key]
    [MaxLength(128)]
    public string? Id { get; set; }

    [MaxLength(256)]
    public string PersonName { get; set; }

    public short PersonAge { get; set; }

// ommitted other properties

now, I have a form like this in ASP Core in the frontend

@model Person


<form action="/api/new-person">
    <input form="PersonName"/>
    <button type="submit"></button>
</form>

As you can see, I only have PersonName in my form, in my backend I only want to be able to update the Person object in my database for the value of PersonName because it is property that exists in the form, again, this is a simplified example because my object is massive and it changes just about all the time, now, I don’t want to painstakingly set each properties in the backend such as

var existingPersonFromDatabase = await _appDbContext.User.FirstOrDefaultAsync(x=>x.Id == formPerson.Id);

existingPersonFromDatabase.PersonName = formPerson.PersonName;

existingPersonFromDatabase.PersonAge = formPerson.PersonAge ;
// + settings 20 more properties one by one

so the question here is, how do i make it so that i only have to update the fields existing in the form?