display2.java

管理学生信息

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;
import java.util.*;
import java.sql.*;
class Display2 extends JFrame{
	ResultSet rs1=null,rs2=null,rs3=null;
	Display2(ResultSet rs){
		super("显示列表");
		setSize(500,450);
		//setLayout(new GridLayout(20,1));
		setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
		this.rs1=rs;

		String str[]=new String[]{"课程名","课号","学分","任课教师","选课人数","平均成绩"};
		DefaultTableModel model=new DefaultTableModel();
		for(int i=0;i<str.length;i++)
			model.addColumn(str[i]);
		JTable table=new JTable(model);
		table.setPreferredScrollableViewportSize(new Dimension(450, 400));
		JScrollPane scroll=new JScrollPane(table);
		JPanel scrollPanel=new JPanel();
		scrollPanel.add(scroll);
		add(scrollPanel);

/*		Label lb1[]=new Label[6];
		Panel k=new Panel();
		GridLayout buju=new GridLayout();
		k.setLayout(buju);
		buju.setColumns(6);
		String str[]=new String[]{"课程名","课号","学分","任课教师","选课人数","平均成绩"};
		for (int i=0;i<6 ;i++ )
		{
			lb1[i]=new Label(str[i]);
			k.add(lb1[i]);
		}
		add(k);*/
			
		Connection con=null,con2=null;
		Statement sm=null,sm2=null;
		String command=null,command2;
		try{
			//DriverManager.registerDriver(new com.microsoft.jdbc.sqlserver.SQLServerDriver());
			Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
			con=DriverManager.getConnection("jdbc:odbc:student");
			con2=DriverManager.getConnection("jdbc:odbc:student");
		}catch(Exception ex){
		System.out.println(ex.getMessage());
		return;
		}
		try{
			while(rs1.next()){	
					sm=con.createStatement();
					sm2=con2.createStatement();
					command="select count(*) as number,avg(sc.grade) as average "
						+"from sc where cno='"+rs1.getString("cno")+"'"
						+" group by cno";
					command2="select cname,cno,cgrade,teacher from ch where cno='"+rs1.getString("cno")+"'";
					rs3=sm2.executeQuery(command2);
					rs2=sm.executeQuery(command);
					if(rs3.next())
					{
					//	JPanel p=new JPanel();
					//	p.setLayout(new GridLayout(1,6));
					//	JLabel a[]=new JLabel[6];//
						try{
							String stk[]=new String[6];
							stk[0]=rs3.getString(1).trim();
							stk[1]=rs3.getString(2).trim();
							stk[2]=rs3.getString(3).trim();
							stk[3]=rs3.getString(4).trim();
							if(rs2.next())
							{
								stk[4]=rs2.getString(1).trim();
								stk[5]=rs2.getString(2).trim();
							}
							else 
							{
								stk[4]="空";
								stk[5]="空";
							}
							model.addRow(stk);
						/*	for(int i=0;i<6;i++)
							{
								a[i]=new JLabel(stk[i]);
								p.add(a[i]);
							}*/
						}catch(SQLException e)
						{
							System.out.println(e.getMessage());
						}
						//add(p);
					}
					rs3.close();
					rs2.close();
					sm.close();
					sm2.close();
				}
			}catch(SQLException ez){
				System.out.println(ez.getMessage());
			}
		try{
			con2.close();
			con.close();
			dispose();
		}catch(Exception ez){}
		validate();
		setVisible(true);
		}
}