// Query using a custom operation:
// custom discount information for all products
private IDataList QueryProductCustomDiscount()
{
// get OrderDetails table
dynamic od = workspace.table(Utils.OrderDetails.Name);
// aggregate OrderDetails table
dynamic qp = workspace.query("query_productCustomDiscount", new
{
ds = MyOp.ProgressiveDiscount(od.UnitPrice, od.Discount, od.Quantity), // calculate discount for a product in an order
Product = od.ProductID, // group by product
OrderCount = Op.Count(od.OrderID), // order count for a product
DiscountSum = Op.Sum("ds") // total progressive discount for a product in all orders
});
return(qp.Query.Execute());
}
// products within specified unit price range
private IDataList QueryUnitPriceRange()
{
double from = (double)nudUnitPriceFrom.Value;
double to = (double)nudUnitPriceTo.Value;
// get OrderDetails table
dynamic od = workspace.table(Utils.OrderDetails.Name);
// aggregate OrderDetails table
dynamic qr = workspace.query("query_range", new
{
_range = od.UnitPrice.Gte(from).Lte(to), // narrow data to the specified unit price range
ds = Op.Mul(od.UnitPrice, od.Discount), // calculate the discount for a product in an order
Price = od.UnitPrice, // group by UnitPrice
OrdersCount = Op.Count(od.OrderID), // how many times products with the same price were ordered
MaxDiscount = Op.Max("ds") // what is the maximum discount for products with the same price
});
return(qr.Query.Execute());
}