SELECT * FROM
pessoal AS t0, pessoal AS t1
WHERE
t0.sexo = 0 AND t0.sexo != t1.sexo;

SELECT COUNT(*) FROM pessoal WHERE sexo = 0 AND salario >= 1000;

SELECT grupo, AVG(salario) FROM pessoal GROUP BY grupo;

public void paintComponent(Graphics graphics) {
Graphics2D g = (Graphics2D) graphics;

final double RADIUS = 10;
final double[] X = { x0, x1, x2, x3, x4 };
final double[] Y = { y0, y1, y2, y3, y4 };

for ( int i = 0; i < X.length; i++ ) {
g.draw( new Ellipse2D.Double(X[i],Y[i],RADIUS*2,RADIUS*2));
}
}

Lista de Países
EUA 100 0
Japão 90 1
China 80 1
Alemanha 70 0
Brasil 60 1

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;

public class App {

public static void main(String[] args) {
File file = new File("input.txt");

try {

Scanner scanner = new Scanner(file);
scanner.nextLine();

int count = 0;

while (scanner.hasNextLine()) {
String country = scanner.next();
int value = scanner.nextInt();
int enable = scanner.nextInt();

if ( enable == 1 )
count += value;
}
scanner.close();

System.out.println(count);

} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
}

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

public class App extends JFrame {
public App() {
super("Fundatec");

JPanel panel = new JPanel();
panel.setLayout( new FlowLayout() );

JButton btn = new JButton("Ok");
btn.addMouseListener( new MouseListener() {

public void mouseEntered(MouseEvent e) {
System.out.print("A");
}

public void mouseExited(MouseEvent e) {
System.out.print("B");
}
public void mouseReleased(MouseEvent e) {
System.out.print("C");
}
public void mousePressed(MouseEvent e) {
System.out.print("D");
}
public void mouseClicked(MouseEvent e) {
System.out.print("E");
}
});

panel.add(btn);
add(panel);
}

static public void main(String[] args) {
App app = new App();
app.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
app.setSize( 200, 75 );
app.setVisible( true );
}
}

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

public class App extends JFrame {
public App() {
super("Fundatec");

JPanel panel = new JPanel();
panel.setLayout( new BorderLayout() );

panel.add( new JButton("Btn 1"), BorderLayout.NORTH );
panel.add( new JButton("Btn 2"), BorderLayout.SOUTH );

add(panel);
}

static public void main(String[] args) {
App app = new App();
app.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
app.setSize( 200, 200 );
app.setVisible( true );
}
}

class App {

static private void concatena(String s1, String s2) {
s1 = s1 + s2;
s2 = "";
}

static public void main(String[] args) {
String s1 = "Fundatec";
String s2 = "Concursos";

concatena(s1, s2);

System.out.println(s1 + " " + s2);

}
}