How can I clear the loaded data before loading the data into the table?

I am making a small inventory control system. This is the invoice table of my database.

The columns are inid(p), itid(p), cuid(p), itname, qty, sprice, total, isdate, redate.
This is the "Invoices" interface when searching for old invoices using the Invoice ID (inid). I have searched for one. Every data is properly set up as text fields and tables. But the problem is when I search another invoice, the other data will be set correctly but the table is not clear and the data of the second search will also be set to the given table under the data of the first search.


This is the second search interface.
Given below is my search source code.

JDBC db = new JDBC();
public boolean b;   

  public void selectFromDate(JComboBox combodate, JDateChooser isdate, JDateChooser redate,       DateSpinner retime, DateSpinner istime,
          JTable jtable1, JTextField txtCuid, JTextField txtCuName, JTextField txtCuAdd,
          JTextField txtCuTp, JTextField txtgtotal, JTextField txtAdvance, JTextField txtDue,
          JTextField txtInvoiceID, JTextField txtDamage, JTextField txtInvoiceTotal) {
      SimpleDateFormat formatter1 = new SimpleDateFormat("yyyy-MM-dd");
    SimpleDateFormat formatter2 = new SimpleDateFormat("HH:mm:ss");
    try {
        ResultSet rs1 = db.getData("SELECT * FROM invoice WHERE isdate='" + combodate.getSelectedItem().toString() + "'");
        if (rs1.next()) {
            b = true;
            while (rs1.next()) {                    
                txtInvoiceID.setText((rs1.getString("inid")));
            Vector v = new Vector();
            DefaultTableModel dd = (DefaultTableModel) jtable1.getModel();
               dd.setRowCount(0);
            v.add(rs1.getInt("itid"));
            v.add(rs1.getString("itname"));
            v.add(rs1.getInt("qty"));
            v.add(rs1.getDouble("sprice"));
            v.add(rs1.getDouble("total"));
            dd.addRow(v);

            String maindate1 = rs1.getString("isdate");
            String date1 = maindate1.substring(0, 10);
            String time1 = maindate1.substring(11, 19);

            Date d1 = formatter1.parse(date1);
            Date t1 = formatter2.parse(time1);

            isdate.setDate(d1);
            istime.setValue(t1);

            String maindate2 = rs1.getString("redate");
            String date2 = maindate2.substring(0, 10);
            String time2 = maindate2.substring(11, 19);

            Date d = formatter1.parse(date2);
            Date t = formatter2.parse(time2);

            redate.setDate(d);
            retime.setValue(t);


            try {
                ResultSet rs2 = db.getData("SELECT * FROM customer WHERE cuid='" + rs1.getInt("cuid") + "'");
                while (rs2.next()) {
                    txtCuid.setText(String.valueOf(rs1.getInt("cuid")));
                    txtCuName.setText(rs2.getString("cuname"));
                    txtCuAdd.setText(rs2.getString("cuadd"));
                    txtCuTp.setText(rs2.getString("cutp"));

                    try {
                        ResultSet rs3 = db.getData("SELECT * FROM indetails WHERE inid='" + rs1.getInt("inid") + "'");
                        if (rs3.first()) {
                            txtgtotal.setText(String.valueOf(rs3.getDouble("gtotal")));
                            txtAdvance.setText(String.valueOf(rs3.getDouble("advance")));
                            txtDue.setText(String.valueOf(rs3.getDouble("due")));
                            try {
                                ResultSet rs4 = db.getData("SELECT * FROM infinal WHERE inid=" + rs1.getInt("inid") + "");
                                if (rs4.first()) {
                                    txtDamage.setText(String.valueOf(rs4.getDouble("dcost")));
                                    txtInvoiceTotal.setText(String.valueOf(rs4.getDouble("intotal")));

                                } else {
                                    JOptionPane.showMessageDialog(null, "Invoice is not finalised");
                                }
                            } catch (Exception e) {
                                JOptionPane.showMessageDialog(null, this.getClass().getName() + " " + "rs4" + e);
                            }
                        }
                    } catch (Exception e) {
                        JOptionPane.showMessageDialog(null, this.getClass().getName() + " " + "rs3" + e);
                    }
                }
            } catch (Exception e) {
                JOptionPane.showMessageDialog(null, this.getClass().getName() + " " + "rs2" + e);
            }
            }

        } else {
            b = false;
            JOptionPane.showMessageDialog(null, this.getClass().getName() + " " + "rs1");
        }
    } catch (Exception e) {
        JOptionPane.showMessageDialog(null, this.getClass().getName() + "rs1 " + " " + e);
    }
}
}

When I comment dd.setRowCount(0); I just get the same result. please help me.
My JDBC class code.

package Model;

import static Model.JDBC.con;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.Statement;
import javax.swing.JOptionPane;

public class JDBC {

String driver = "com.mysql.jdbc.Driver";
String url = "jdbc:mysql://localhost/cateringnew";
static Connection con;
//10.226.50.130

private void setCon() {
    try {
        Class.forName(driver);
        con = DriverManager.getConnection(url, "root", "");
    } catch (Exception ex) {
        JOptionPane.showMessageDialog(null, ex);
    }
}

private Connection getCon() throws Exception {
    if (con == null) {
        setCon();
        System.out.println("setCon");
    }
    System.out.println("getCon");
    return con;
}


  public void putData(String sql) {
    try {
        PreparedStatement state = getCon().prepareStatement(sql);
        state.executeUpdate();
        System.out.println("putDate");

    } catch (Exception ex) {
        JOptionPane.showMessageDialog(null, ex);
    }
}

public ResultSet getData(String sql) throws Exception {

    Statement state = getCon().createStatement();
    ResultSet rset = state.executeQuery(sql);
    System.out.println("getData");
    return rset;
  }
 }