public List <StockOut> soldItems(DateTime startDate, DateTime endDate) { List <StockOut> allSales = new List <StockOut>(); using (SqlConnection connection = new SqlConnection(connectionString)) { SqlCommand cmd = new SqlCommand(); cmd.CommandText = " SELECT * FROM tbl_SalesSheet WHERE StockOutTime BETWEEN @StartTime AND @EndTime;"; cmd.Parameters.AddWithValue("@StartTime", startDate); cmd.Parameters.AddWithValue("@EndTime", endDate); cmd.Connection = connection; connection.Open(); SqlDataReader reader = cmd.ExecuteReader(); while (reader.Read()) { StockOut aSale = new StockOut(); aSale.GetSales(reader["ItemName"].ToString(), Convert.ToInt32(reader["Quantity"])); allSales.Add(aSale); } reader.Read(); connection.Close(); return(allSales); } }