Vbnet+billing+software+source+code | Free Forever

Public Sub ExecuteNonQuery(ByVal query As String) Try OpenConnection() cmd = New SqlCommand(query, conn) cmd.ExecuteNonQuery() Catch ex As Exception MessageBox.Show("Error: " & ex.Message) Finally CloseConnection() End Try End Sub End Module Secure authentication using salt-hash (simplified here for demo).

Dim invoiceNo As String = "INV-" & DateTime.Now.ToString("yyyyMMddHHmmss") Dim customerID As Integer = GetOrCreateCustomer(txtCustomerMobile.Text) ' Function to fetch/add customer Dim userId As Integer = CurrentUserID ' Assume global login user ID vbnet+billing+software+source+code

Public Sub OpenConnection() ' Change Data Source according to your SQL Server instance conn = New SqlConnection("Data Source=.\SQLEXPRESS;Initial Catalog=BillingDB;Integrated Security=True") If conn.State = ConnectionState.Closed Then conn.Open() End If End Sub vbnet+billing+software+source+code