How to update (update) JTable with data from database

Question

I am trying to update JTable after adding or removing a record from the database (MS Access), but it does not work. Also, I don't understand why the column names are not displayed. Here is my code:

 package Administrator13_03_13; public class Arsti2 { JFrame main = new JFrame("Ārst"); JPanel tP = new JPanel(); JPanel bP = new JPanel(); JButton one = new JButton("Test"); JTable table = new JTable(); DefaultTableModel model; Vector columnNames = new Vector(); Vector data = new Vector(); Arsti2() { main.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); main.setSize(840,300); try { Class.forName("sun.jdbc.odbc.JdbcOdbcDriver"); String Base = "jdbc:odbc:Driver={Microsoft Access Driver (*.mdb)}; DBQ=SL.mdb"; Connection con = DriverManager.getConnection(Base,"",""); Statement st = con.createStatement(); ResultSet res = st.executeQuery("SELECT * FROM Arsti"); ResultSetMetaData rsmd = res.getMetaData(); int column = rsmd.getColumnCount(); columnNames.addElement("ID"); columnNames.addElement("Vards"); columnNames.addElement("Uzvards"); columnNames.addElement("Dzimums"); columnNames.addElement("Personas kods"); columnNames.addElement("Telefona numurs"); columnNames.addElement("Nodalas ID"); columnNames.addElement("Amata ID"); while(res.next()) { Vector row = new Vector(column); for(int i=1; i<=column; i++) { row.addElement(res.getObject(i)); } data.addElement(row); } model = new DefaultTableModel(data,columnNames); table.setModel(model); //model.fireTableDataChanged(); tP.add(table); bP.add(one); main.add(tP,BorderLayout.NORTH); main.add(bP,BorderLayout.SOUTH); } catch(Exception e) { e.printStackTrace(); } main.setVisible(true); one.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent evnt1) { model.fireTableDataChanged(); } }); } public static void main(String[] args) { new Arsti2(); } } 

Answer 1

Just model.fireTableDataChanged(); does not work, you need to reload your model from the database This should work:

 public class Arsti2 { JFrame main = new JFrame("Ārst"); JPanel tP = new JPanel(); JPanel bP = new JPanel(); JButton one = new JButton("Test"); JTable table = new JTable(); DefaultTableModel model; Vector columnNames = new Vector(); Vector data = new Vector(); Arsti2() { main.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); main.setSize(840,300); try { reloadData(); model = new DefaultTableModel(data,columnNames); table.setModel(model); //model.fireTableDataChanged(); tP.add(table); bP.add(one); main.add(tP,BorderLayout.NORTH); main.add(bP,BorderLayout.SOUTH); } catch(Exception e) { e.printStackTrace(); } main.setVisible(true); one.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent evnt1) { try { reloadData(); model.fireTableDataChanged(); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }); } private void reloadData() throws ClassNotFoundException, SQLException { columnNames.clear(); data.clear(); Class.forName("sun.jdbc.odbc.JdbcOdbcDriver"); String Base = "jdbc:odbc:Driver={Microsoft Access Driver (*.mdb)}; DBQ=SL.mdb"; Connection con = DriverManager.getConnection(Base,"",""); Statement st = con.createStatement(); ResultSet res = st.executeQuery("SELECT * FROM Arsti"); ResultSetMetaData rsmd = res.getMetaData(); int column = rsmd.getColumnCount(); columnNames.addElement("ID"); columnNames.addElement("Vards"); columnNames.addElement("Uzvards"); columnNames.addElement("Dzimums"); columnNames.addElement("Personas kods"); columnNames.addElement("Telefona numurs"); columnNames.addElement("Nodalas ID"); columnNames.addElement("Amata ID"); while(res.next()) { Vector row = new Vector(column); for(int i=1; i<=column; i++) { row.addElement(res.getObject(i)); } data.addElement(row); } } public static void main(String[] args) { new Arsti2(); } } 

Answer 2

Also I don't understand why my column names are not displayed

Column names will not be displayed unless you add a container to it (e.g. JScrollPane).

add(new JScrollPane(table));

should be enough.