For this sample, I simply created an ASP.NET 3.5 web site project (using Visual Studio 2008 beta 2) and dragged a GridView on to a web page. Added a class "Employee.vb" to the project as following (code removed for clarity):
Imports Microsoft.VisualBasic
Public Class Employee
...
Public Sub New(ByVal e As Integer, ByVal en As String, ByVal s As Double, ByVal d As Integer) ...
Public Property Empno() As Integer ...
Public Property Ename() As String ...
Public Property Sal() As Double ...
Public Property Deptno() As Integer ...
End Class
Added a new method (to generate data) to the web page as following:
Private Function GetEmployeeList() As List(Of Employee)
Dim EmpList As New List(Of Employee)
EmpList.Add(New Employee(1001, "Jagadish", 3400, 20))
EmpList.Add(New Employee(1002, "Chatarji", 6700, 30))
EmpList.Add(New Employee(1003, "Pulakhandam", 3200, 10))
EmpList.Add(New Employee(1004, "Winner", 7800, 20))
EmpList.Add(New Employee(1005, "Sunitha Paruchuri", 6500, 30))
EmpList.Add(New Employee(1006, "Malli", 4200, 20))
EmpList.Add(New Employee(1007, "Ram Mullangi", 6200, 30))
EmpList.Add(New Employee(1008, "Veditha Davuluri", 7600, 10))
EmpList.Add(New Employee(1009, "Jyothi", 8900, 10))
EmpList.Add(New Employee(1010, "Srinivas", 6900, 20))
EmpList.Add(New Employee(1011, "Krishna", 2300, 30))
EmpList.Add(New Employee(1012, "Chandra Kamala", 5400, 30))
Return EmpList
End Function
Now, let us consider the following SQL SELECT statement:
SELECT ename FROM emp
The corresponding LINQ statement (along with execution code) for the above SQL is as follows:
Protected Sub form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles form1.Load
If Not IsPostBack Then
Dim query = From p In GetEmployeeList() Select p.Ename
Me.GridView1.DataSource = query
Me.GridView1.DataBind()
End If
End Sub
The only important statement from the above is the following:
Dim query = From p In GetEmployeeList() Select p.Ename
which selects only the property (or column) "Ename" of every successive object available in "p" from the collection returned by "GetEmployeeList()"
Selecting more columns:
Further, the following SQL SELECT
SELECT ename, sal FROM emp
can be coded in LINQ as following:
Dim query = From p In GetEmployeeList() Select p.Ename, p.Sal
Columns with Expressions:
The following SQL SELECT
SELECT ename, sal * 12 AS AnnSal FROM emp
can be coded in LINQ as following:
Dim query = From p In GetEmployeeList() Select p.Ename, AnnSal = (p.Sal * 12)
Make sure that Column Alias is compulsory in LINQ, if more than one column is available in the list.
Working with DISTINCT:
The following SQL SELECT
SELECT DISTINCT deptno FROM emp
can be coded in LINQ as following:
Dim query = From p In GetEmployeeList() Select p.Deptno Distinct
Working with ORDER BY:
The following SQL SELECT
SELECT ename, sal FROM emp ORDER BY ename
can be coded in LINQ as following:
Dim query = From p In GetEmployeeList() Select p.Ename, p.Sal Order By Ename
We can also make use of Alias columns as part of ORDER BY operator as following:
Dim query = From p In GetEmployeeList()
Select p.Ename, Annsal = (p.Sal * 12)
Order By Annsal Descending
Tools 
