C# 如何取回所有“客户”对象以及在LINQtoSQL中仅“打开”的“订单”？

我知道如何获得客户及其所有订单：

//Get data context for the SQL Server connection
DataContext connection = new DataContext(getConnection());

//Customer table to query against
Table<Customer> customers = connection.GetTable<Customer>();

//This query gives all customers and ALL their orders
IQueryable<Customer> query = 
    from customer in customer
    where customer.id == custId select customer;

---

您可以在第一次查询后直接查询客户，因为它是一个IQueryable so

var onlyOpen = customer.where(x=> x.orders._status = "Open");

---

我可以使用DataLoadOptions完成此操作：

var onlyOpen = customer.where(x=> x.orders._status = "Open");

public virtual void addAssociationFilter<T>(Expression<Func<T, object>> filter, DataContext dataContext)
{
    //We'll use this to restrict our main object's entity list property
    DataLoadOptions restrictList = new DataLoadOptions();

    //We only want ops that are current or finished
    restrictList.AssociateWith<T>(filter);

    //Set on our context
    dataContext.LoadOptions = restrictList;
}

//Call like:
addAssociationFilterJCustomer>(
    cust => cust.orders.Where(o => o.status == "Open"),
    dataContext
);