How to: Execute a Query that Returns a Primitive Type

This article is relevant to entity models that utilize the deprecated Visual Studio integration of Telerik Data Access. The current documentation of the Data Access framework is available here.

This topic provides examples of how to execute queries that return a primitive type.

To run the code in this example, you need to create a new Telerik Data Access Domain Model based on the Northwind database.

The following code is the LINQ example.

using (EntitiesModel dbContext = new EntitiesModel())
{
   IQueryable<Int32> orderIdQuery = 
        from order in dbContext.Orders
        where order.CustomerID == "ALFKI" || order.CustomerID == null
        select order.OrderID;

   // Iterate through the collection of values.
   foreach (Int32 id in orderIdQuery)
   {
       Console.WriteLine("{0}", id);
   }

   IQueryable<DateTime?> orderDateQuery = 
        from order in dbContext.Orders
        where order.CustomerID == "ALFKI" || order.CustomerID == null
        select order.OrderDate;

   // Iterate through the collection of values.
   foreach (DateTime? orderDate in orderDateQuery)
   {
       string orderDateMessage = "OrderDate not set";
       if (orderDate != null)
       {
           orderDateMessage = orderDate.ToString();
       }
       Console.WriteLine("Ship Date: {0}.", orderDateMessage);
   }
}
Using dbContext As New EntitiesModel()
 Dim orderIdQuery As IQueryable(Of Int32) = From order In dbContext.Orders
              Where order.CustomerID = "ALFKI" OrElse order.CustomerID Is Nothing
              Select order.OrderID
 ' Iterate through the collection of values.
 For Each id As Int32 In orderIdQuery
  Console.WriteLine("{0}", id)
 Next id
 Dim orderDateQuery As IQueryable(Of Date?) = From order In dbContext.Orders
                Where order.CustomerID = "ALFKI" OrElse order.CustomerID Is Nothing
                Select order.OrderDate
 ' Iterate through the collection of values.
 For Each orderDate? As Date In orderDateQuery
  Dim orderDateMessage As String = "OrderDate not set"
  If orderDate IsNot Nothing Then
   orderDateMessage = orderDate.ToString()
  End If
  Console.WriteLine("Ship Date: {0}.", orderDateMessage)
 Next orderDate
End Using

See Also

How to: Return a Specific Object Using its Key
How to: Order Two Unionized Queries
How to: Page Through Query Results