这是一个JDBC项目。来自WAMP服务器上MySQL
数据库的数据显示在JTable
中。我想在我的JSpinner
上输入一个用户输入的ID,以便从表中删除带有该ID的行。我做了一个SQL查询,一切正常,但我的JTable
上的数据在执行查询时不会刷新。我单击我的JNazad
按钮(我的后退按钮),然后重新进入该窗口,以便我的JTable
显示刷新的数据。我没有在FireTableModel
方法中实施NapraviTablicu
,因为它的DefaultTableModel
和更新都是自动完成的。我不知道自己做错了什么:
public class GUIBDelete extends JFrame{
private SpinnerModel SM;
private JSpinner Spinner;
private JLabel LUnos;
private JButton BNazad, BIzvrsi;
private String ID, SqlQuery;
private Vector NaziviKolona = new Vector();
private Vector Podaci = new Vector();
private JTable Tablica=new JTable();
private JScrollPane ScrollPane;
private DefaultTableModel model;
private JTable NapraviTablicu(){
try {
String SqlQuery = "SELECT * FROM `nfc_baza`";
Podaci.clear();
NaziviKolona.clear();
Class.forName("com.mysql.jdbc.Driver");
Connection con = DriverManager.getConnection("jdbc:mysql://"
+ "localhost:3306/nfc", "root", "");
Statement Stat = con.createStatement();
ResultSet Rez = Stat.executeQuery(SqlQuery);
ResultSetMetaData md = Rez.getMetaData();
int columns = md.getColumnCount();
for (int i = 1; i <= columns; i++) {
NaziviKolona.addElement(md.getColumnName(i));
}
while (Rez.next()) {
Vector red = new Vector(columns);
for (int i = 1; i <= columns; i++) {
red.addElement(Rez.getObject(i));
}
Podaci.addElement(red);
}
Rez.close();
Stat.close();
con.close();
} catch (Exception e) {
System.out.println(e);
}
model = new DefaultTableModel(Podaci, NaziviKolona);
JTable table = new JTable(model);
return table;
}
ActionListener a1 = new ActionListener() {
public void actionPerformed(ActionEvent a) {
dispose();
new GUIIzbornik();
}
};
ActionListener a2 = new ActionListener() {
public void actionPerformed(ActionEvent a) {
ID=null;
SqlQuery = "DELETE FROM `nfc`.`nfc_baza` WHERE `nfc_baza`.`ID` = ";
IzvrsiQuery();
}
private void IzvrsiQuery() {
Object sp = Spinner.getValue();
ID = sp.toString();
SqlQuery=SqlQuery+ID;
try {
Class.forName("com.mysql.jdbc.Driver");
Connection con2 = DriverManager.getConnection(
"jdbc:mysql://" + "localhost:3306/nfc", "root", "");
Statement Stat = con2.createStatement();
int Rez = Stat.executeUpdate(SqlQuery);
Stat.close();
con2.close();
JOptionPane.showMessageDialog(null, "Uspješno izvrseno!",
"Poruka!", JOptionPane.INFORMATION_MESSAGE);
} catch (Exception e) {
System.out.println(e);
}
}
};
GUIBDelete(){
setLayout(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
Tablica=NapraviTablicu();
ScrollPane = new JScrollPane(Tablica);
c.fill = GridBagConstraints.BOTH;
c.insets = new Insets(2, 2, 2, 2);
c.weightx = 0.1;
c.weighty = 0.1;
c.gridwidth = 4;
c.gridheight = 2;
c.gridx = 0;
c.gridy = 0;
add(ScrollPane, c);
LUnos= new JLabel("<html><br>Unesite ID elementa</br> kojeg želite obrisati:<html>");
c.gridx = 0;
c.gridy = 2;
c.gridwidth = 1;
c.gridheight = 1;
add(LUnos, c);
SM = new SpinnerNumberModel(1, 1, 1000, 1);
Spinner = new JSpinner(SM);
c.gridx = 2;
c.gridy = 2;
c.gridwidth = 2;
add(Spinner, c);
BNazad = new JButton("Nazad");
c.gridx = 0;
c.gridy = 3;
c.gridwidth = 1;
BNazad.addActionListener(a1);
add(BNazad, c);
BIzvrsi = new JButton("Izvrši");
c.gridx = 2;
c.gridy = 3;
BIzvrsi.addActionListener(a2);
add(BIzvrsi, c);
setSize(400, 500);
setTitle("Brisanje podataka");
setVisible(true);
setLocationRelativeTo(null);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
GUIBDelete i = new GUIBDelete();
}
});
}
}
答案 0 :(得分:1)
看起来您正在从数据库表中删除一行,并且您希望JTable
反映更改。在izvrsiQuery()
更新您的TableModel
,JTable
将自行更新。例如,
...
con2.close();
model.removeRow(((Number)(spinner.getValue())).intValue() - 1);
JOptionPane.showMessageDialog(...);
...
请注意,行号从0
开始,使用RowSorter
时必须翻译它们。
另外,如果您使用常见的Java命名约定并将因子分解出来,那么您的代码将更容易被其他人阅读。
附录:该示例只是按编号删除一行。您必须在TableModel
中搜索与已删除的ID
对应的行。
附录:虽然不太实用,但您可能希望在使用setModel()
进行DML操作后从数据库刷新整个表格,如图here所示。