如何通过WCF使用LinqToSql维护子对象？

public void UpdateParentWithChild(Parent parent)
{
    // 在这里维护子对象
}

public void UpdateParentWithChild(Parent parent)
{
    using (MyDataContext context = new MyDataContext())
    {
        // 获取父对象
        Parent existingParent = context.Parents.Where(p => p.ParentID == parent.ParentID).FirstOrDefault();

        // 如果父对象存在，则更新子对象
        if (existingParent != null)
        {
            // 更新子对象
            Child child = parent.Child;
            if (child.ChildID == 0)
            {
                // 添加新的子对象
                context.Children.InsertOnSubmit(child);
            }
            else
            {
                // 更新现有的子对象
                Child existingChild = context.Children.Where(c => c.ChildID == child.ChildID).FirstOrDefault();
                if (existingChild != null)
                {
                    existingChild.Name = child.Name;
                    existingChild.Age = child.Age;
                }
            }

            // 提交更改
            context.SubmitChanges();
        }
    }
}

Parent parent = new Parent();
parent.ParentID = 1;
parent.Name = "John";

Child child = new Child();
child.ChildID = 1;
child.Name = "Jane";
child.Age = 5;

parent.Child = child;

MyServiceClient client = new MyServiceClient();
client.UpdateParentWithChild(parent);
client.Close();