EF Core继承与延迟加载问题及方案遗留疑问

问题场景 #

基于.NET 6.0 + EF Core 6.0.21 + Microsoft.EntityFrameworkCore.SqlServer 6.0.19开发时，遇到实体继承与延迟加载的关联异常。定义的实体类如下：

public class Pool
{        
    public int Id { get; set; }
    public virtual Profile? Profile { get; set; }
    public int? AProfileId { get; set; }
    public int? BProfileId { get; set; }
}

public abstract class Profile
{
    public Profile() { }
    public int Id { get; set; }
}

public class AProfile : Profile
{
    public AProfile() { }
    public virtual Pool? Pool { get; set; } 
}

public class BProfile : Profile
{
    public BProfile() { }
    public virtual Pool? Pool { get; set; } 
}

public class CProfile : Profile
{
    public CProfile() { }
    // CProfile 无 Pool 属性
}

// 其他 Profile 子类

通过HasOne配置AProfile、BProfile与Pool的一对一关系并启用延迟加载后，出现两个问题：

1. 检索Pool对象时，aPool.Profile为空（但AProfileId字段有值），bPool.Profile却能正常加载；
2. 尝试将AProfile关联到Pool.Profile时抛出异常：

System.InvalidOperationException: 'The instance of entity type 'AProfile' cannot be tracked as the entity type 'BProfile' because the two types are not in the same hierarchy.'

已尝试的解决方案 #

经@sorosh_sabz建议，修改Pool类实现代理属性并重配关系：

public class Pool
{
    public int Id { get; set; }

    public Profile? Profile
    {
        get
        {
            return ORMAProfileAccessor as Profile ?? ORMBProfileAccessor;
        }

        set
        {
            switch (value)
            {
                case AProfile aProfile:
                    ORMAProfileAccessor = aProfile;
                    break;
                case BProfile bProfile:
                    ORMBProfileAccessor = bProfile;
                    break;
                default:
                    throw new InvalidCastException("Invalid profile type");
            }
        }
    }

    internal virtual AProfile? ORMAProfileAccessor { get; set; }
    internal virtual BProfile? ORMBProfileAccessor { get; set; }
}

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<AProfile>().HasOne(P => P.Pool).WithOne(Q => Q.ORMAProfileAccessor).HasForeignKey<Pool>("AProfileId").IsRequired(false);
    modelBuilder.Entity<BProfile>().HasOne(P => P.Pool).WithOne(Q => Q.ORMBProfileAccessor).HasForeignKey<Pool>("BProfileId").IsRequired(false);
    modelBuilder.Entity<Pool>().Ignore(P => P.Profile);
}

该方案能正确更新数据库外键，但检索Pool对象时Profile字段仍为空；单独检索Profile实例时，其关联的Pool字段可正常加载。

疑问 #

需要额外配置什么才能让Pool的Profile字段实现自动填充？

内容的提问来源于stack exchange，提问作者f soltanzadeh