I want to update data

Question

I'm a beginner in programming in Java. I can display data from mySQL database in a JTabe.But I want to modify/ update table data. I could not update my database table using the sun's JDBCAdapter. is there any better way ?
Thank you for your help.

Answer 1

Dear Friend,
In fact, i have created a database in mysql. After that i displayed the database in Jtable using the JDBC. But i can't updating the table data from JDBC. I have used the sun's JDBCAdapter.java code with my program. After running the programme, when i modify the table a message comes that-" Not sending update to database ". I am attached the code.Can you suggest me where i will put the update statement for database table update. ?
pitab/**
* @(#)JDBCAdapter.java     1.6 98/02/10
* Copyright (c) 1997 Sun Microsystems, Inc. All Rights Reserved.
* This software is the confidential and proprietary information of Sun
* Microsystems, Inc. ("Confidential Information"). You shall not
* disclose such Confidential Information and shall use it only in
* accordance with the terms of the license agreement you entered into
* with Sun.
* SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF THE
* SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
* IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
* PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR ANY DAMAGES
* SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR DISTRIBUTING
* THIS SOFTWARE OR ITS DERIVATIVES.
* An adaptor, transforming the JDBC interface to the TableModel interface.
* @version 1.20 09/25/97
* @author Philip Milne
import java.util.Vector;
import java.sql.*;
import javax.swing.table.AbstractTableModel;
import javax.swing.event.TableModelEvent;
public class JDBCAdapter extends AbstractTableModel {
Connection connection;
Statement statement;
ResultSet resultSet;
String[] columnNames = {};
Class[] columnTpyes = {};
Vector          rows = new Vector();
ResultSetMetaData metaData;
public JDBCAdapter(String url, String driverName,
String user, String passwd) {
try {
Class.forName(driverName);
System.out.println("Opening db connection");
connection = DriverManager.getConnection(url, user, passwd);
statement = connection.createStatement();
catch (ClassNotFoundException ex) {
System.err.println("Cannot find the database driver classes.");
System.err.println(ex);
catch (SQLException ex) {
System.err.println("Cannot connect to this database.");
System.err.println(ex);
public void executeQuery(String query) {
if (connection == null || statement == null) {
System.err.println("There is no database to execute the query.");
return;
try {
resultSet = statement.executeQuery(query);
metaData = resultSet.getMetaData();
int numberOfColumns = metaData.getColumnCount();
columnNames = new String[numberOfColumns];
// Get the column names and cache them.
// Then we can close the connection.
for(int column = 0; column < numberOfColumns; column++) {
columnNames[column] = metaData.getColumnLabel(column+1);
// Get all rows.
rows = new Vector();
while (resultSet.next()) {
Vector newRow = new Vector();
for (int i = 1; i <= getColumnCount(); i++) {
     newRow.addElement(resultSet.getObject(i));
rows.addElement(newRow);
// close(); Need to copy the metaData, bug in jdbc:odbc driver.
fireTableChanged(null); // Tell the listeners a new table has arrived.
catch (SQLException ex) {
System.err.println(ex);
public void close() throws SQLException {
System.out.println("Closing db connection");
resultSet.close();
statement.close();
connection.close();
protected void finalize() throws Throwable {
close();
super.finalize();
// Implementation of the TableModel Interface
// MetaData
public String getColumnName(int column) {
if (columnNames[column] != null) {
return columnNames[column];
} else {
return "";
public Class getColumnClass(int column) {
int type;
try {
type = metaData.getColumnType(column+1);
catch (SQLException e) {
return super.getColumnClass(column);
switch(type) {
case Types.CHAR:
case Types.VARCHAR:
case Types.LONGVARCHAR:
return String.class;
case Types.BIT:
return Boolean.class;
case Types.TINYINT:
case Types.SMALLINT:
case Types.INTEGER:
return Integer.class;
case Types.BIGINT:
return Long.class;
case Types.FLOAT:
case Types.DOUBLE:
return Double.class;
case Types.DATE:
return java.sql.Date.class;
default:
return Object.class;
public boolean isCellEditable(int row, int column) {
try {
return metaData.isWritable(column+1);
catch (SQLException e) {
return false;
public int getColumnCount() {
return columnNames.length;
// Data methods
public int getRowCount() {
return rows.size();
public Object getValueAt(int aRow, int aColumn) {
Vector row = (Vector)rows.elementAt(aRow);
return row.elementAt(aColumn);
public String dbRepresentation(int column, Object value) {
int type;
if (value == null) {
return "null";
try {
type = metaData.getColumnType(column+1);
catch (SQLException e) {
return value.toString();
switch(type) {
case Types.INTEGER:
case Types.DOUBLE:
case Types.FLOAT:
return value.toString();
case Types.BIT:
return ((Boolean)value).booleanValue() ? "1" : "0";
case Types.DATE:
return value.toString(); // This will need some conversion.
default:
return "\""+value.toString()+"\"";
public void setValueAt(Object value, int row, int column) {
try {
String tableName = metaData.getTableName(column+1);
// Some of the drivers seem buggy, tableName should not be null.
if (tableName == null) {
System.out.println("Table name returned null.");
String columnName = getColumnName(column);
String query =
"update "+tableName+
" set "+columnName+" = "+dbRepresentation(column, value)+
" where ";
// We don't have a model of the schema so we don't know the
// primary keys or which columns to lock on. To demonstrate
// that editing is possible, we'll just lock on everything.
for(int col = 0; col<getColumnCount(); col++) {
String colName = getColumnName(col);
if (colName.equals("")) {
continue;
if (col != 0) {
query = query + " and ";
query = query + colName +" = "+
dbRepresentation(col, getValueAt(row, col));
System.out.println(query);
System.out.println("Not sending update to database");
// statement.executeQuery(query);
catch (SQLException e) {
// e.printStackTrace();
System.err.println("Update failed");
Vector dataRow = (Vector)rows.elementAt(row);
dataRow.setElementAt(value, column);
}