Not getting the desired row displayed

[Fungsuk Wangdu]

I am learning JDBC, completely new to it. I know MySQL very well. I have a search form in my applet (tab 2), where I search for food. And when I click search, I want it to search for the exact food from the Database and return the table contents of that particular row alone. But I am not getting any result. Only an empty frame opens. But when I put the query as "SELECT * FROM table", I am getting the complete table. But I want only one row, the one that is searched for. Can anyone please tell me where I am going wrong? Here's my code:

import java.awt.*;
import java.awt.event.*;
import java.sql.DriverManager;
import java.util.Vector;
import javax.swing.*;
import com.mysql.jdbc.*;

public class Tryout extends JFrame  implements ActionListener {

        private static final long serialVersionUID = 1L;

        final Vector columnNames = new Vector();
        final Vector data = new Vector();

        private JTabbedPane tabbedPane = new JTabbedPane();
        private JPanel inputpanel;
        private JPanel searchpanel;
        public String s;

        public Tryout()  {          
                inputpanel = createPage1();
                searchpanel = createPage2();
                tabbedPane.addTab("Input Form", inputpanel);
                tabbedPane.addTab("Search Form", searchpanel);
                this.add(tabbedPane, BorderLayout.CENTER);           
        }

        public JPanel createPage1()  {          
            JPanel panel = new JPanel();
            panel.setLayout(new GridBagLayout());
            GridBagConstraints c = new GridBagConstraints();
            //Some code
            return panel;            
        }

        public JPanel createPage2() {      

                JPanel panel = new JPanel();
                panel.setLayout(new GridBagLayout());
                GridBagConstraints c = new GridBagConstraints();
                c.anchor = GridBagConstraints.LINE_START;
                c.weightx = 0.5;
                c.weighty = 0.5;
                JLabel region = new JLabel("Enter Region"); 
                c.anchor = GridBagConstraints.FIRST_LINE_START;
                c.gridx = 0;
                c.gridy = 0;
                panel.add(region, c);
                JTextField field = new JTextField(20);
                c.anchor = GridBagConstraints.FIRST_LINE_START;
                c.gridx = 1;
                c.gridy = 0;
                panel.add(field, c);
                JButton search = new JButton("SEARCH");               
                c.anchor = GridBagConstraints.FIRST_LINE_START;
                c.gridx = 2;
                c.gridy = 0;
                panel.add(search, c);
                s = field.getText();
                search.addActionListener(new ActionListener() {

                    public void actionPerformed(ActionEvent ae){

                    try{
                    Connection con = null;
                    Class.forName("com.mysql.jdbc.Driver");
                    con = (Connection) DriverManager.getConnection("jdbc:mysql://localhost:3306/delikat", "root", "");
                    Statement st = (Statement) con.createStatement();
                    ResultSet rs= (ResultSet) st.executeQuery("SELECT * FROM delicious WHERE name = "+s+"");
                    ResultSetMetaData md = (ResultSetMetaData) rs.getMetaData();
                    int columns = md.getColumnCount();
                    for (int i = 1; i <= columns; i++) {
                    columnNames.addElement( md.getColumnName(i) );
                    }
                    while (rs.next()) {
                    Vector row = new Vector(columns);
                    for (int i = 1; i <= columns; i++) {
                    row.addElement( rs.getObject(i) );
                    }
                    data.addElement( row );
                    }
                    rs.close();
                    st.close();
                    }
                    catch(Exception e) {}
                    JFrame tab=new JFrame();
                    JTable table = new JTable(data, columnNames);
                    JScrollPane scrollPane = new JScrollPane( table );
                    tab.add( scrollPane );
                    tab.setVisible(true);
                    tab.setSize(300,100);
                    }
                    });
                return panel;
        }

        public static void main(String args[]) {
                SwingUtilities.invokeLater(new Runnable() {
                        @Override
                        public void run() {
                                Tryout ex = new Tryout();
                                ex.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                                ex.setSize(500,500);
                                ex.setVisible(true);
                        }
                });
        }       
}

My table has the following fields: id, name, category, origin, taste, type.

Can anyone please check out the code on your comp, try it out and help me with it?

Thanks

[T Mishra]

"SELECT * FROM delicious WHERE name = "+s+""

The problem is in the sql query syntax.

[Fungsuk Wangdu]

I tried your Query too. Even that doesn't work. Can anyone please try this out in Eclipse and tell me?

[Martin Vashko]

Fungsuk Wangdu wrote:I tried your Query too.

What T Mishra posted is your query, singled out so as to help you spot the problem with the syntax. Do you see what is wrong with it? (Hint: what is the syntax to enter string literals in MySQL queries?)

Instead of fixing the syntax, you should actually switch to using PreparedStatements. They make your code more efficient, portable and secure. See our page on PreparedStatement.