Date Only cannot be mapped SQL Server 2019

Question

I am trying to use the new DateOnly aspects of c# but when I come to do my migrations I am having the following issue. I am using SQL Server 2019 the error is.

'Amenitie.StartDate could not be mapped because it is of type 'DateOnly', which is not a supported primitive type or a valid entity type. Either explicitly map this property, or ignore it using the'

My model is as follows

public class Amenitie
{
    public int? Id { get; set; }
    public Rooms? Rooms { get; set; }
    public string? Description { get; set; }
    public DateOnly StartDate { get; set; }
    public DateOnly EndDate { get; set; }
    public bool? isAvailable { get; set; }
    public bool? isDeleted { get; set; }
    public bool? isActive { get; set; }
    public DateTime? LastModifiedBy { get; set; }
    public DateTime? CreateDate { get; set; }
}

My Dal project and my web project are both set to

<PropertyGroup>
  <TargetFramework>net6.0</TargetFramework>
  <Nullable>enable</Nullable>
</PropertyGroup>

I am using the following package versions.

<ItemGroup>
 <PackageReference Include="Microsoft.AspNetCore.Identity" Version="2.2.0" />
 <PackageReference Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore" Version="5.0.9" />
 <PackageReference Include="Microsoft.EntityFrameworkCore" Version="5.0.9" />
 <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="5.0.9">
 <PrivateAssets>all</PrivateAssets>
 <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
 </PackageReference>
 <PackageReference Include="Microsoft.EntityFrameworkCore.Relational.Design" Version="2.0.0-preview1-final" />
 <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="5.0.9" />
 <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer.Design" Version="2.0.0-preview1-final" />
 <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="5.0.9">
  <PrivateAssets>all</PrivateAssets>
  <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
 </PackageReference>
 <PackageReference Include="Microsoft.Extensions.Configuration" Version="5.0.0" />
</ItemGroup>

Is DateOnly available in EF Core 6 and above I presume?

Answer 1

Try this

public class YourDbContext : DbContext
{
    Ctors() {...}

    protected override void ConfigureConventions(ModelConfigurationBuilder builder)
    {
        builder.Properties<DateOnly>()
                .HaveConversion<DateOnlyConverter>()
                .HaveColumnType("date");
    }
}
              
/// <summary>
/// Converts <see cref="DateOnly" /> to <see cref="DateTime"/> and vice versa.
/// </summary>
public class DateOnlyConverter : ValueConverter<DateOnly, DateTime>
{
   /// <summary>
   /// Creates a new instance of this converter.
   /// </summary>
   public DateOnlyConverter() : base(
       d => d.ToDateTime(TimeOnly.MinValue),
       d => DateOnly.FromDateTime(d))
  { }
}

EDIT: with RC2 this does not work for nullable types.

EDIT 2: with NET6 release version this works for nullable types again, and more than that, you dont need to have a separate converter for "DateOnly?" anymore.

EDIT 3: with NET 8 built-in support has been added and the only thing you need to do is:

public class YourDbContext : DbContext
{
    Ctors() {...}

    protected override void ConfigureConventions(ModelConfigurationBuilder builder)
    {
        builder.Properties<DateOnly>()
           .HaveColumnType("date");
    }
}