Fill dataset with VB.Net and Oracle database

Email.aspx.vb

Imports System.Data
Imports System.IO
Imports System.Threading
Imports System.Net
Imports System.Net.Mail
Imports Project.EmailService
Imports Oracle.DataAccess.Client

Partial Class Email
  Public Const Page_Name As String = "email.aspx"
  Dim dsEmail As New DataSet
  Dim allEmails As String = ""
  Dim emailService As New EmailService
  
  Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Dim connectStr As String = ConfigurationManager.ConnectionStrings("ConnectionString").ConnectionString
        dsEmail = emailService.GetEmailsByPageName(Page_Name)
        For Each table As DataTable In dsEmail.Tables
            For Each dr As DataRow In table.Rows
                Dim rdrEmail = dr("email").ToString() + ","
                allEmails = allEmails + rdrEmail
            Next
            allEmails = allEmails.Substring(0, allEmails.Length - 1)
        Next


        Dim Mail As New MailMessage
        Dim smtp As New SmtpClient
        If Application("mailcounter") = 0 Then
            With Mail
                .From = New MailAddress("Test@Email.com")
                .To.Add(allEmails)
                .IsBodyHtml = True
                .Subject = "Test Email Subject"
                .Body = "Test Email Body"
            End With

            'send the message 
            smtp = New SmtpClient("smtp.mail")
            With smtp
                .DeliveryMethod = SmtpDeliveryMethod.Network
                .Port = 25
                .UseDefaultCredentials = True
                Try
                    .Send(Mail)
                    Application("mailcounter") = 1
                Catch exp As Exception
                    Dim str As String
                    str = exp.Message
                End Try
            End With
        End If
  End Sub

EmailRepository.vb

Imports Microsoft.VisualBasic
Imports Oracle.DataAccess
Imports System.Data
Imports Oracle.DataAccess.Client

Public Class EmailRepository
  Function GetEmailsByPageName(ByVal pageName As String) As DataSet
        Dim cn As New OracleConnection
        Dim cmd As New OracleCommand

        cn = New OracleConnection
        cn.ConnectionString = (ConfigurationManager.ConnectionStrings("ConnectionString").ConnectionString)

        cmd = New OracleCommand("ORACLEDBA.PACKAGE_EMAIL.SP_EMAIL_LISTING_BY_NAME")
        cmd.CommandType = Data.CommandType.StoredProcedure
        cmd.Connection = cn
        cmd.BindByName = True

        Dim paramCursor As OracleParameter = New OracleParameter("email_list_cursor", OracleDbType.RefCursor)
        With cmd.Parameters
            .Add(New OracleParameter("a_page_name", OracleDbType.Varchar2)).Value = pageName
            .Add("a_err_code", OracleDbType.Int32, Data.ParameterDirection.Output)
            .Add("a_err_msg", OracleDbType.Varchar2, 300).Direction = Data.ParameterDirection.Output
            .Add(paramCursor).Direction = Data.ParameterDirection.Output
        End With

        Dim da As New OracleDataAdapter(cmd)
        Dim dsEmail As DataSet = New DataSet
        Try
            da.SelectCommand = cmd
            da.Fill(dsEmail)
            Return dsEmail
        Catch ex As Exception
            Throw
        Finally
            da.Dispose()
            cmd.Dispose()
            cn.Dispose()
            If cn.State = ConnectionState.Open Then
                cn.Close()
            End If
        End Try
    End Function
End Class    

EmailService.vb

Imports Microsoft.VisualBasic
Imports System.Data
Imports Project.EmailRepository

Public Class EmailService
    Dim emailRepository As New EmailRepository
    
    Function GetEmailsByPageName(ByVal pageName As String) As DataSet
        GetEmailsByPageName = emailRepository.GetEmailsByPageName(pageName)
    End Function
End Class