小编Yau*_*nka的帖子

我无法弄清楚如何在表格中放入大量数据.数据不得重复

建议,可能还有其他方法吗？

create table COUNTRIES (
  COUNTRY_ID   VARCHAR2(7),
  COUNTRY_NAME VARCHAR2(40),
  constraint COUNTRY_C_ID_PK primary key (COUNTRY_ID)
);


Begin
For IDS in 1..1000000
Loop
INSERT INTO "SYSTEM"."COUNTRIES" (COUNTRY_ID, COUNTRY_NAME) VALUES (dbms_random.string('L', 7), dbms_random.string('L', 15));
Commit;
End loop;
End; 

我的英语不好,但我会尽力解释.我有个问题.在JPanel我画线....他们应该超出对象的区域JPanel和JScrollPane理论上应该显示整个面板,但它没有更新,也没有显示为面板范围发布的所有行.

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.Console;

import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;

public class TestFrame extends JFrame {

    static int speed = 10;
    static int floor = 22;
    public static void createGUI() {
        JFrame frame = new JFrame("Test frame");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        final Font font = new Font("Verdana", Font.PLAIN, 25);

        JPanel butPanel = new JPanel();     

        JButton biginButton = new JButton("start");
        biginButton.setFont(font);
        biginButton.setFocusable(false);
        butPanel.add(biginButton);

        JButton remButton …