在 JTable java 中获取更多行

Question

我编写了自动建议组合框。功能是，

*当用户在任一组合框中键入第一个字母时，数据从 MySQL 数据库中检索并显示在弹出列表中，当用户单击建议的项目时，然后按添加按钮将该项目添加到 J 表中并清除组合框

但是当我从组合框中选择另一个项目并单击添加按钮之前添加的一个消失

*根据上述情况如何在J表中保留Both或多个item *

我将发布我的代码：

private void NamecomboActionPerformed(java.awt.event.ActionEvent evt) {                                          
    String drugname = (String) Namecombo.getSelectedItem();
    try{

    String name = "SELECT * FROM druginfo WHERE ItemName LIKE '"+drugname+"%'";

    PreparedStatement pstmt = conn.prepareStatement(name);
    ResultSet rs = pstmt.executeQuery();

    while (rs.next()){
        IDcombo.setSelectedItem(rs.getString("ItemID"));  
    }

    }catch(Exception e){
      JOptionPane.showMessageDialog(null,"error "+ e);
    }



}                                         

private void IDcomboActionPerformed(java.awt.event.ActionEvent evt) {                                        
    String drugid = (String) IDcombo.getSelectedItem();
    try{

    String name = "SELECT * FROM druginfo WHERE ItemID LIKE '"+drugid+"%'";

    PreparedStatement pstmt = conn.prepareStatement(name);
    ResultSet rs = pstmt.executeQuery();

    while (rs.next()){
        Namecombo.setSelectedItem(rs.getString("ItemName"));  
    }

    }catch(Exception e){
      JOptionPane.showMessageDialog(null,"error "+ e);
    }
    try{

    String exp = "SELECT ExpDate FROM druginfo WHERE ItemID LIKE '"+drugid+"%'";
    PreparedStatement pstmt = conn.prepareStatement(exp);
    ResultSet rs2 = pstmt.executeQuery();

    while (rs2.next()){
        String date = rs2.getString("ExpDate");

        exptxt.setText(date);
    }

    }catch(Exception e){
      JOptionPane.showMessageDialog(null,"error "+ e);
    }
} 

为将项目添加到 JTable 执行的添加按钮操作；

private void add_btnActionPerformed(java.awt.event.ActionEvent evt) {                                        

        String temp = (String) IDcombo.getSelectedItem();
        String sql = "select ItemID,ItemName,CostPrice,InStock from druginfo where ItemID=?";
    try {   
        pst=conn.prepareStatement(sql);
        pst.setString(1, temp);
        rs=pst.executeQuery();
        tableSale.setModel(DbUtils.resultSetToTableModel(rs));
        IDcombo.setSelectedItem(null);
        Namecombo.setSelectedItem(null);
    } catch (Exception ex) {
       JOptionPane.showMessageDialog(null, ex);
    }

Answer 1

将当前选择（结果集数据）添加到 JTable 对象而不替换旧数据。

rs=pst.executeQuery();
addDataToTable(tableSale,DbUtils.resultSetToTableModel(rs));
IDcombo.setSelectedItem(null);
Namecombo.setSelectedItem(null);

//ADD this method
public void addDataToTable(JTable table,TableModel model) {
    DefaultTableModel tableModel = (DefaultTableModel) table.getModel();
    DefaultTableModel resultSetModel = (DefaultTableModel) model;
    for (int i = 0; i < resultSetModel.getRowCount(); i++) {
        Vector row=new Vector();
        for (int j = 0; j < resultSetModel.getColumnCount(); j++) {
            row.addElement(resultSetModel.getValueAt(i, j));
        }
        tableModel.addRow(row);
    }
    tableModel.fireTableDataChanged();
}

Answer 2

这个tableSale.setModel(DbUtils.resultSetToTableModel(rs)); 将用新模型替换旧模型。所以显然数据会丢失。你必须为现有模型添加值。我添加了一个sn-p，它将帮助你。

将tableSale.setModel(DbUtils.resultSetToTableModel(rs)); 替换为addValuesToModel(DbUtils.resultSetToTableModel(rs));

addValuesToModel(DbUtils.resultSetToTableModel(rs));

public void addValuesToModel(TableModel resultModel) {
    DefaultTableModel tmodel = (DefaultTableModel) tableSale.getModel();
    DefaultTableModel rmodel = (DefaultTableModel) resultModel;
    for (int i = 0; i < rmodel.getRowCount(); i++) {
        Object[] row = new Object[rmodel.getColumnCount()];
        for (int j = 0; j < rmodel.getColumnCount(); j++) {
            row[j] = rmodel.getValueAt(i, j);
        }
        tmodel.addRow(row);
    }
}