Dim con As New Data.SqlClient.SqlConnection("Server=ServerSQL;Initial Catalog=ITWarehouse;Integrated Security=SSPI")
        Dim cmd As New Data.SqlClient.SqlCommand()
        cmd.CommandText= "SQL запрос"
cmd.Connection = con
        Try
            con.Open()
            Dim reader As Data.SqlClient.SqlDataReader = cmd.ExecuteReader(Data.CommandBehavior.SingleRow)
            reader.Read()
            If reader.HasRows = False Then --Если False значит ничего не вернулось в запросе.