在EF Core 6.0中将导航显示为不同类型

Question

我使用的是EF Core 6.0，不知道在给定简化示例的情况下，以下内容是否可以将导航公开/配置为不同的类型？如果是，怎么办？

在我的DDD实体中，公开为不同的类型(即ISomeChildInterface而不是SomeChild(是可取的，因为我希望ParentClass.Children[0].FirstName等可以访问(从我的中介处理程序(，但不能访问ParentClass.Children[0].SomeMethod()，以保护我在ParentClass.CallSomeChildMethod()中的业务规则/不变量。

还要注意我目前是如何使用.AutoInclude()和.HasQueryFilter()的，如果这有区别的话。

当我尝试创建迁移时，我得到了一个错误导航"SomeParent.Children"未找到。请在配置实体类型之前将导航添加到实体类型。

public interface ISomeChildInterface
{
Guid Id { get; }
string FirstName { get; }
string LastName { get; }
}
public class SomeChildClass : ISomeChildInterface
{
public Guid Id { get; private set; }
public string FirstName { get; private set; } = null!;
public string LastName { get; private set; } = null!;
//parameterless constructor required by EF Core
private SomeChildClass()
{
}
//private constructor
private SomeChildClass(string firstName, string lastName)
{
Id = Guid.NewGuid();
FirstName = firstName;
LastName = lastName;
}
//Static factory create method
public static SomeChildClass Create(string firstName, string lastName)
{
return new SomeChildClass(firstName, lastName);
}
public void SomeMethod()
{
}
}
public class ParentClass
{
private readonly List<SomeChildClass> _children = new();
public IReadOnlyCollection<ISomeChildInterface> Children => _children.AsReadOnly();
public void AddChild(SomeChildClass someChild)
{
_children.Add(someChild);
}
public void CallSomeChildMethod(Guid childId)
{
// Some business rules etc 
_children.SingleOrDefault(x => x.id => childId).SomeMethod();
}
}
public class SomeContext : IdentityContext
{
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
// ... snip ...
_ = modelBuilder.Entity<ParentClass>(entity =>
{
_ = entity.Navigation(x => x.Children).AutoInclude().HasField("_children").UsePropertyAccessMode(PropertyAccessMode.Field);
//_ = entity.HasQueryFilter(e => UserRoles.Any(x => x.UserId == CurrentUserId && x.RoleId == e.RoleId));
}
}
}

Answer 1

否，ParentClass.Children不能是导航属性，但您可以将导航属性设为私有属性。例如

builder.Entity<ParentClass>().HasMany("_children").WithOne();

但是您将无法在转换为SQL的查询中使用ParentClass.Children。