LINQ to SQL - Why can't you use a WHERE after an ORDER BY?
- by MCS
The following code:
// select all orders
var orders = from o in FoodOrders
where o.STATUS = 1
order by o.ORDER_DATE descending
select o;
// if customer id is specified, only select orders from specific customer
if (customerID!=null)
{
orders = orders.Where(o => customerID.Equals(o.CUSTOMER_ID));
}
gives me the following error:
Cannot implicitly convert type 'System.Linq.IQueryable' to 'System.Linq.IOrderedQueryable'. An explicit conversion exists (are you missing a cast?)
I fixed the error by doing the sorting at the end:
// select all orders
var orders = from o in FoodOrders
where o.STATUS = 1
select o;
// if customer id is specified, only select orders from specific customer
if (customerID!=null)
{
orders = orders.Where(o => customerID.Equals(o.CUSTOMER_ID));
}
// I'm forced to do the ordering here
orders = orders.OrderBy(o => o.ORDER_DATE).Reverse();
But I'm wondering why is this limitation in place? What's the reason the API was designed in such a way that you can't add a where constraint after using an order by operator?
