dotnet
Unfulfillable nullable contraints are set for complex types with TPH entities
Usually, if a field has the Required attribute it is mapped as nullable: false.
But if this field is declared in a TPH entity, that condition may not be possible.
Unfortunately, required-flaged fields within complex types are set as NOT NULL anyway, which prevents persisting entities that do not implement those fields.
Core for reproduction
Migrations are required (Add-Migration Init -c CustomContext5)
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Diagnostics;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
namespace ConsoleApp5
{
internal static class Program5
{
public static void Test(string[] args)
{
var supplier = new Supplier() { Name = "Supplier", Extra = new() { Field = "Field" } };
var customer = new Customer() { Name = "Customer" };
using (var ctx = new CustomContext5())
{
ctx.Database.Migrate();
ctx.Add(supplier);
ctx.SaveChanges();
ctx.Add(customer);
ctx.SaveChanges();
}
Console.WriteLine("Done!");
Console.ReadLine();
}
public class CustomContext5 : DbContext
{
public DbSet<Contact> Contacts { get; set; }
public DbSet<Supplier> Suppliers { get; set; }
public DbSet<Customer> Customers { get; set; }
protected override void OnConfiguring(DbContextOptionsBuilder builder)
{
builder.LogTo(Console.WriteLine, new[] { RelationalEventId.CommandExecuting }).EnableSensitiveDataLogging();
builder.UseSqlServer(@"Server=(localdb)\mssqllocaldb;Database=TestDb;Trusted_Connection=True");
}
protected override void OnModelCreating(ModelBuilder builder)
{
builder.Entity<Contact>().HasDiscriminator(e => e.Discriminator);
}
}
public abstract class Contact
{
public int Id { get; set; }
public string? Discriminator { get; set; }
public string? Name { get; set; }
}
public class Supplier : Contact
{
[Required]
public string? AnotherExtra { get; set; }
public required Extra Extra { get; set; }
}
public class Customer : Contact
{
}
[ComplexType]
public class Extra
{
[Required]
public string? Field { get; set; }
}
}
}
Include provider and version information
EF Core version: 8.0.1 Database provider: Microsoft.EntityFrameworkCore.SqlServer
Minor note: This also affects atomic field types such as int and bool that are not flagged with Required.
problem is in RelationalPropertyExtensions.IsColumnNullable - there we try to compute nullability of a column that the given property is mapped to. For inheritance scenario we look at declaring type and check if it's part of TPH. However for property of a complex type, declaring type is that complex type so we don't do the proper check. We should find the parent non-complex type instead
