With regards to another thread, http://www.daniweb.com/forums/thread251069.html on how to compare the current date to retrieve relevant data (Details there), now I have issue on storing this query result on a VB.net variable.
It works in this way. It is an academic work to do a ecommerce website, and I need to compute some tax imposed on the goods purchased. Relevant subtotal etc has been implemented except on computing the tax. It is supposed to be a function and I have coded it in this way:
Public Function computeTaxCharge(ByVal dblSubTotal As Double) As Double Dim dblTaxRate As Double Dim dblTaxCharge As Double Dim strConn As String strConn = ConfigurationManager.ConnectionStrings("AppDb").ToString Dim conn As New SqlConnection(strConn) Dim strSql As String strSql = "SELECT Top 1 TaxRate" & _ "FROM GST" & _ "WHERE EffectiveDate <= @dt" & _ "ORDER BY EffectiveDate DESC" ' Define an Command object to execute the SQL statement Dim cmd1 As New SqlCommand(strSql, conn) cmd1.Parameters.AddWithValue("@Dt", System.DateTime.Now()) ' Open database connection conn.Open() ' Execute the Insert SQL cmd1.ExecuteNonQuery() ' Define a data adapter to fetch data Dim da As New SqlDataAdapter(cmd1) 'Create a dataset Dim ds As New DataSet ' Fetch data to a table da.Fill(ds, "dblTaxRate") ' Define a data table to hold the data fetched Dim dt As New DataTable ' Close database connection conn.Close() dblTaxCharge = dblSubTotal * dblTaxRate / 100 Return dblTaxCharge End Function
But it crashes on
How should I do? Thank you in advance.