Hi,

I have demonstrate a very good example to to create a webservice which will be used to authenticate user on the website against predefined database entry.

So this is a very basic yet useful example to further enhance webservice capability on the site.

I have used back-end database as SQL Server 7 and created a database named "Credentials" and created a table named "UserInfo"

Table Structure
===============

UserID char 10
Password char 6

So please create database and table then run the example.


I have commented the code already to give you an idea of how the things happen. So please go through the code if you still have any problem then please let me know.

Thanks,

Best Regards,



--------------------------------------------------------------------------------



Imports System.Web.Services
Imports System.data.OleDb
_
Public Class Service1
Inherits System.Web.Services.WebService

#Region " Web Services Designer Generated Code "

Public Sub New()
MyBase.New()

'This call is required by the Web Services Designer.
InitializeComponent()

'Add your own initialization code after the InitializeComponent() call

End Sub

'Required by the Web Services Designer
Private components As System.ComponentModel.IContainer

'NOTE: The following procedure is required by the Web Services Designer
'It can be modified using the Web Services Designer.
'Do not modify it using the code editor.
Private Sub InitializeComponent()
components = New System.ComponentModel.Container()
End Sub

Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
'CODEGEN: This procedure is required by the Web Services Designer
'Do not modify it using the code editor.
If disposing Then
If Not (components Is Nothing) Then
components.Dispose()
End If
End If
MyBase.Dispose(disposing)
End Sub

#End Region

' WEB SERVICE EXAMPLE
' The HelloWorld() example service returns the string Hello World.
' To build, uncomment the following lines then save and build the project.
' To test this web service, ensure that the .asmx file is the start page
' and press F5.
'
' _
'Public Function HelloWorld() As String
' Return "Hello World"
'End Function

_
Public Function Login(ByVal UserID As String, ByVal Password As String) As Boolean
'Retrived password retrieval and initalization
Dim pass As String = RetrieveData(UserID)
'Password matching after trimming all the spaces
If Trim(pass) = Trim(Password) Then
'if matched then notify back to calling application that user is valid by setting return parameter to true
Login = True
Else
'if not matched then notify back to calling application that user is invalid by setting return parameter to false
Login = False
End If
End Function



Public Function RetrieveData(ByVal UserID As String) As String
Try
Dim connstr As String = "Provider=SQLOLEDB;Data Source=(local);Initial Catalog=Credentials;User ID=sa;"
Dim i As Integer
Dim myConnection As OleDbConnection
Dim myCommand As OleDbDataAdapter
Dim ds As New DataSet
myConnection = New OleDbConnection(connstr)
myCommand = New OleDbDataAdapter("Select * from UserInfo where UserID='" & UserID & "'", myConnection)
myCommand.Fill(ds, "UserInfo")
Return ds.Tables("UserInfo").Rows(0).Item("Password").ToString
Catch
Return ""
End Try
End Function


End Class