Functions - Entity Framework 6 Recipes - page 377

using (var context = new EFRecipesEntities())
{
Console.WriteLine("Using eSQL query...");
string sql = @"Select value i from
EFRecipesModel.GetInvoices(EFRecipesEntities.Invoices) as i
where i.Date > DATETIME'2013-05-1 00:00'
and i.Customer.City = @City";
var objectContext = (context as IObjectContextAdapter).ObjectContext;
var invoices = objectContext.CreateQuery<Invoice>(sql,
new ObjectParameter("City", "Dallas")).Include("Customer");
foreach (var invoice in invoices)
{
Console.WriteLine("Customer: {0}\tInvoice for: {1}, Amount: {2}",
invoice.Customer.Name, invoice.Description, invoice.Amount);
}
}
using (var context = new EFRecipesEntities())
{
Console.WriteLine();
Console.WriteLine("Using LINQ query...");
DateTime date = DateTime.Parse("5/1/2013");
var invoices = from invoice in
MyFunctions.GetInvoices(context.Invoices)
where invoice.Date > date
where invoice.Customer.City == "Dallas"
select invoice;
foreach (var invoice in ((DbQuery<Invoice>)invoices)
.Include("Customer"))
{
Console.WriteLine("Customer: {0}, Invoice for: {1}, Amount: {2}",
invoice.Customer.Name, invoice.Description, invoice.Amount);
}
}
}
}
public class MyFunctions
{
[EdmFunction("EFRecipesModel", "GetInvoices")]
public static IQueryable<Invoice> GetInvoices(IQueryable<Invoice> invoices)
{
return invoices.Provider.CreateQuery<Invoice>(
Expression.Call((MethodInfo) MethodInfo.GetCurrentMethod(),
Expression.Constant(invoices,
typeof(IQueryable<Invoice>))));
}
}