Question

我有以下（保持非常简单）：

public class Customer
{
    public int Id {get; set}
    public IEnumerable<Reminder> Reminders {get; set}
    public IEnumerable<Order> Orders {get; set}
}

public class Reminder
{
    public int CustomerId {get; set}
    public string Text {get; set}
}

public class Order
{
    public int CustomerId {get; set}
    public int CategoryId {get; set}
}

public class OrderDetails
{
    public int OrderId {get; set}
    public int ProductId {get; set}
}

我也使用通用存储库模式，我使用嵌套实体加载实体，如下所示：

    public virtual T Get(int id, params Expression<Func<T, object>>[] include)
    {
        if (include.Any())
        {
            var set = include.Aggregate<Expression<Func<T, object>>, IQueryable<T>>
                        (dbset, (current, expression) => current.Include(expression));

            return set.SingleOrDefault<T>(x => x.Id == id);
        }

        return dbset.Find(id);
    }

使用Linq，我想加载一个客户，他所有的提醒和所有订单（及其详细信息）都有一个特定的CategoryId。所以我试着这样做：

var customer = customerRepository.Get(10, x => x.Reminders, x => x.Orders.Select(o => o.OrderDetails));

但上面加载了一切。如果我执行以下操作，则会抛出异常：

var customer = customerRepository.Get(10, x => x.Reminders, x => x.Orders.Where(c => c.CategoryId == categoryId).Select(o => o.OrderDetials));

那么我怎样才能真正只返回我需要的订单？

渴望加载嵌套实体

0 个答案: