Jan 02

QueryViewer.java: An interactive database query viewer

# QueryViewer.java  An interactive database query viewer. Connects to the specified Oracle or Sybase database, executes a query, and presents the results in a JTable. Uses the following file:

    * DBResultsTableModel.java Simple class that tells a JTable how to extract relevant data from a DBResults object (which is used to store the results from a database query). 
############################################################################

  package cwp;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;

/** An interactive database query viewer. Connects to
 *  the specified Oracle or Sybase database, executes a query,
 *  and presents the results in a JTable.
 *  

*/ public class QueryViewer extends JFrame implements ActionListener{ public static void main(String[] args) { new QueryViewer(); } private JTextField hostField, dbNameField, queryField, usernameField; private JRadioButton oracleButton, sybaseButton; private JPasswordField passwordField; private JButton showResultsButton; Container contentPane; private JPanel tablePanel; public QueryViewer () { super("Database Query Viewer"); WindowUtilities.setNativeLookAndFeel(); addWindowListener(new ExitListener()); contentPane = getContentPane(); contentPane.add(makeControlPanel(), BorderLayout.NORTH); pack(); setVisible(true); } /** When the "Show Results" button is pressed or * RETURN is hit while the query textfield has the * keyboard focus, a database lookup is performed, * the results are placed in a JTable, and the window * is resized to accommodate the table. */ public void actionPerformed(ActionEvent event) { String host = hostField.getText(); String dbName = dbNameField.getText(); String username = usernameField.getText(); String password = String.valueOf(passwordField.getPassword()); String query = queryField.getText(); int vendor; if (oracleButton.isSelected()) { vendor = DriverUtilities.ORACLE; } else { vendor = DriverUtilities.SYBASE; } if (tablePanel != null) { contentPane.remove(tablePanel); } tablePanel = makeTablePanel(host, dbName, vendor, username, password, query); contentPane.add(tablePanel, BorderLayout.CENTER); pack(); } // Executes a query and places the result in a // JTable that is, in turn, inside a JPanel. private JPanel makeTablePanel(String host, String dbName, int vendor, String username, String password, String query) { String driver = DriverUtilities.getDriver(vendor); String url = DriverUtilities.makeURL(host, dbName, vendor); DBResults results = DatabaseUtilities.getQueryResults(driver, url, username, password, query, true); JPanel panel = new JPanel(new BorderLayout()); if (results == null) { panel.add(makeErrorLabel()); return(panel); } DBResultsTableModel model = new DBResultsTableModel(results); JTable table = new JTable(model); table.setFont(new Font("Serif", Font.PLAIN, 17)); table.setRowHeight(28); JTableHeader header = table.getTableHeader(); header.setFont(new Font("SansSerif", Font.BOLD, 13)); panel.add(table, BorderLayout.CENTER); panel.add(header, BorderLayout.NORTH); panel.setBorder (BorderFactory.createTitledBorder("Query Results")); return(panel); } // The panel that contains the textfields, checkboxes, // and button. private JPanel makeControlPanel() { JPanel panel = new JPanel(new GridLayout(0, 1)); panel.add(makeHostPanel()); panel.add(makeUsernamePanel()); panel.add(makeQueryPanel()); panel.add(makeButtonPanel()); panel.setBorder (BorderFactory.createTitledBorder("Query Data")); return(panel); } // The panel that has the host and db name textfield and // the driver radio buttons. Placed in control panel. private JPanel makeHostPanel() { JPanel panel = new JPanel(); panel.add(new JLabel("Host:")); hostField = new JTextField(15); panel.add(hostField); panel.add(new JLabel(" DB Name:")); dbNameField = new JTextField(15); panel.add(dbNameField); panel.add(new JLabel(" Driver:")); ButtonGroup vendorGroup = new ButtonGroup(); oracleButton = new JRadioButton("Oracle", true); vendorGroup.add(oracleButton); panel.add(oracleButton); sybaseButton = new JRadioButton("Sybase"); vendorGroup.add(sybaseButton); panel.add(sybaseButton); return(panel); } // The panel that has the username and password textfields. // Placed in control panel. private JPanel makeUsernamePanel() { JPanel panel = new JPanel(); usernameField = new JTextField(10); passwordField = new JPasswordField(10); panel.add(new JLabel("Username: ")); panel.add(usernameField); panel.add(new JLabel(" Password:")); panel.add(passwordField); return(panel); } // The panel that has textfield for entering queries. // Placed in control panel. private JPanel makeQueryPanel() { JPanel panel = new JPanel(); queryField = new JTextField(40); queryField.addActionListener(this); panel.add(new JLabel("Query:")); panel.add(queryField); return(panel); } // The panel that has the "Show Results" button. // Placed in control panel. private JPanel makeButtonPanel() { JPanel panel = new JPanel(); showResultsButton = new JButton("Show Results"); showResultsButton.addActionListener(this); panel.add(showResultsButton); return(panel); } // Shows warning when bad query sent. private JLabel makeErrorLabel() { JLabel label = new JLabel("No Results", JLabel.CENTER); label.setFont(new Font("Serif", Font.BOLD, 36)); return(label); } }

Note: Brought from our old site: http://www.salearningschool.com/example_codes/ on Jan 2nd, 2017

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