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Please I a mysql code with java that will able to delete from a table in a database

http://docs.oracle.com/javase/tutorial/jdbc/index.html

http://www.vogella.com/articles/MySQLJava/article.html

http://www.tutorialspoint.com/jdbc/jdbc-sample-code.htm
A sample servlet doing mysql/jdbc.Am currently using it.


public class AdvanceBorder extends HttpServlet {
private static Connection connection;

protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
try {


String username = request.getUserPrincipal().getName();

Class.forName("com.mysql.jdbc.Driver";

Connection conn = getConnection();


PreparedStatement ps = conn.prepareStatement(" Select user_id userId from USERS where username = ?";
ps.setString(1,username);


ResultSet rs = ps.executeQuery();
int userId = 0;
if(rs.next())
userId = rs.getInt("userId";

Query q = em.createQuery("Select a from Roleuser a where a.userId=:userId";
q.setParameter("userId", userId);

List rowz = (List)q.getResultList();

Iterator itil = rowz.iterator();

ArrayList<String> arr = new ArrayList<String>();

HttpSession session = request.getSession();

while(itil.hasNext())
arr.add(((Roleuser)itil.next()).getRolename());
session.setAttribute("arr", arr);

request.getRequestDispatcher("home.jsp".forward(request, response);;
} catch (SQLException ex) {
Logger.getLogger(AdvanceBorder.class.getName()).log(Level.SEVERE, null, ex);
} catch (ClassNotFoundException ex) {
Logger.getLogger(AdvanceBorder.class.getName()).log(Level.SEVERE, null, ex);
}
}


private static Connection getConnection(){

try {
if(connection == null || connection.isClosed() )
{
connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/testengine", "root", "gugusomto";
}
} catch (SQLException ex)
{
Logger.getLogger(AdvanceBorder.class.getName()).log(Level.SEVERE, null, ex);

}
return connection;
}

private static void closeConnection(){
try {
if(connection !=null && !connection.isClosed())
{
connection.close();
}
} catch (SQLException ex) {
Logger.getLogger(AdvanceBorder.class.getName()).log(Level.SEVERE, null, ex);
}
}
scription";
}// </editor-fold>
}