根据日期打印图表

Question

当我在没有where条件的情况下编写sql代码时，我得到了结果。我认为准备好的声明没有从JDateChooser访问日期。

private void datesearchActionPerformed(java.awt.event.ActionEvent evt) {                                           
    try {
        JDBCCategoryDataset dataset = new JDBCCategoryDataset("jdbc:mysql://localhost:10061/goshope","com.mysql.jdbc.Driver","root","tiger");
        String qry= "select  item,SUM(quantity) from bill_electronics where date=?  GROUP BY item";
        ps= con.prepareStatement(qry);
        // String qry= "select item, SUM(quantity)  from bill_electronics GROUP BY (item)";

        SimpleDateFormat sdf=new  SimpleDateFormat(" dd,MM,YYYY");
        String date =datechart.getDateFormatString();
        ps.setDate(1,new java.sql.Date(datechart.getDate().getTime()));
        dataset.executeQuery(qry);
        JFreeChart chart = ChartFactory.createBarChart("Daily Report","item", "qty", dataset, PlotOrientation.VERTICAL,false, true, true);
        BarRenderer renderer = new BarRenderer();
        CategoryPlot plot=null;
        ChartFrame frame =new ChartFrame("Daily Report", chart);
        frame.setVisible(true);
        //  frame.setSize(400,650);
        ChartPanel chartpanel= new ChartPanel(chart);
        panel1.removeAll();
        panel1.add(chartpanel,BorderLayout.CENTER);
        panel1.validate();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

我认为准备好的声明不会从JDateChooser访问日期。如果我提供特定日期或没有＆＃39;其中＆＃39;在sql代码上的条件，然后我得到正确的答案。