How to: Execute a Query that Returns a Primitive Type
This topic provides examples of how to execute queries that return a primitive type.
To run the code in this example, you need a fluent model based on the Northwind database.
The following code is the LINQ example.
using (FluentModel dbContext = new FluentModel())
{
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 FluentModel()
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