ASP.NET

 Protected Sub btnForgot_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnForgot.Click

        Dim ConnectionString As String = "Data Source=|DataDirectory|students.mdb"
        Dim uniqueCode As String = String.Empty

         Using conn As New OleDbConnection(ConnectionString)
            Using cmd As OleDbCommand = conn.CreateCommand

                Try

                  Dim dr As OleDbDataReader

                    'Records to match the supplied email (strEmail)   

                    cmd = New OleDbCommand("SELECT * FROM university WHERE strEmail = @strEmail")

                    conn.Open()
                    cmd.Parameters.AddWithValue("@strEmail", strEmail.Text.Trim())
                    cmd.Parameters.AddWithValue("@strEmail", Convert.ToString(strEmail.Text.Trim()))
                    cmd.Parameters.AddWithValue("@uniqueCode", uniqueCode)
                    cmd = New OleDbCommand("UPDATE university SET uniqueCode=@uniqueCode where strEmail = @strEmail", conn)
                   
                    If dr.HasRows Then

                        dr.Read()

                        'generate uniqueCode

                        uniqueCode = Convert.ToString(System.Guid.NewGuid())

                    End If

                    dr = cmd.ExecuteReader()
                    cmd.ExecuteNonQuery()
                    conn.Close()
                    cmd.Dispose()

                Catch ex As Exception

                    Console.WriteLine(ex.Message)

                End Try
            End Using
        End Using

        'Update the unique random code in the uniqueCode field of the database table

        Dim strBody As New StringBuilder()

        strBody.Append("<a href=http://localhost:2464/SampleApplication/ResetPasswordVB.aspx?emailId=" + strEmail.Text & "&uniqueCode=" & uniqueCode & ">Click here to reset your password</a>")

SMTP code follows

Member 8761667 wrote:

I know there are some errors.

Protected Sub btnForgot_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnForgot.Click
    Const ConnectionString As String = "Data Source=|DataDirectory|students.mdb"
    Dim uniqueCode As String = Guid.NewGuid().ToString("N")
    Dim recordExists As Boolean = False
    
    Using conn As New OleDbConnection(ConnectionString)
        Using cmd As OleDbCommand = conn.CreateCommand()
            cmd.CommandText = "UPDATE university SET uniqueCode = @uniqueCode WHERE strEmail = @strEmail"
            cmd.Parameters.AddWithValue("@uniqueCode", uniqueCode)
            cmd.Parameters.AddWithValue("@strEmail", strEmail.Text.Trim())
            
            conn.Open()
            Dim recordsAffected As Integer = cmd.ExecuteNonQuery()
            If recordsAffected <> 0 Then recordExists = True
        End Using
    End Using
    
    If recordExists Then
        Dim builder As New UriBuilder(Request.Url)
        builder.Path = VirtualPathUtility.ToAbsolute("~/ResetPasswordVB.aspx")
        builder.Query = "uniqueCode=" & HttpUtility.UrlEncode(uniqueCode)
        
        Dim link As String = builder.Uri.ToString()
        ' Eg: http://localhost:2464/SampleApplication/ResetPasswordVB.aspx?uniqueCode=ee3106b4df694555b4ca6f2727a23dc8
        
        ...
    End If
End Sub

Dim recordExists As Boolean = False

Richard Deeming wrote:

store the expiration date in the database, not in the link!