问使用子记录列表保存记录时发生EntityFramework错误

EN

// Get the record from the database
var record = _dbContext.Parents
    .Include(x => p.SomeOtherObject)
    .Include(x => x.ListChildren)
    .FirstOrDefault(x => x.IdParent == id);

// then we do some changes to Parent and ListChildren
// we do not do any changes to SomeOtherObject!!!

// save changes
_dbContext.Update(record);
_dbContext.SaveChanges();

// definition of entities
public class Parent
{
    public int IdParent { get; set; }
    public string Name {get; set;}
    public string Surname {get; set;}

    public int IdSomeOtherObject { get; set; }
    [ForeignKey("IdSomeOtherObject")]
    public virtual SomeOtherObject SomeOtherObject { get; set; }

    public virtual List<Child> ListChildren { get; set; }
}

public class Child
{
    public int IdChild { get; set; }
    public int IdParent { get; set;}
    public string Name { get; set; }
}

public class SomeOtherObject
{
    public int IdSomeOtherObject { get; set; }
    public string PropertiesBlahBla { get; set; }
}