null.java

数据库的连接用java实现的很好用的

import javax.swing.*;
import java.awt.*;
import java.sql.*;
import java.awt.event.*;
public class NULL extends JFrame implements ActionListener 
{
	JTextField tfde=new JTextField();
	JLabel ib=new JLabel("请输入学号：");
	JLabel no=new JLabel("学号：");
	JLabel n=new JLabel("姓名：");
	JLabel s=new JLabel("性别：");
	JLabel a=new JLabel("年龄：");
	JLabel d=new JLabel("系别：");
	JTextField no1=new JTextField();
	//JTextField n1=new JTextField();
	//JTextField s1=new JTextField();
	//JTextField a1=new JTextField();
	//JTextField d1=new JTextField();
	JTextArea ttt=new JTextArea();
	JLabel bb=new JLabel("学生选课系统");
	JButton b=new JButton("查询");
	JTextField ta1=new JTextField();
	JTextField tfde2=new JTextField();
	JLabel ib2=new JLabel("请输入要选择的课程号：");
	JButton b2=new JButton("确定");
	JLabel ib3=new JLabel("你可以选择的课程：");
	JTextArea ta2=new JTextArea();
	JTextArea ta3=new JTextArea();
	public NULL()
	{
		super("学生选课系统查询组件");
		setSize(800,460);
		getContentPane().setLayout(null);
		getContentPane().add(bb);
		bb.setBounds(320,20,140,50);
		getContentPane().add(ib);
		ib.setBounds(10,80,120,20);
		getContentPane().add(tfde);
		tfde.setBounds(130,80,160,20);
		getContentPane().add(b);
		b.setBounds(310,80,70,20);
		getContentPane().add(no);
		no.setBounds(10,110,40,20);
		//getContentPane().add(no1);
		//no1.setBounds(40,110,60,20);
		getContentPane().add(n);
		n.setBounds(90,110,50,20);
		//getContentPane().add(n1);
		//n1.setBounds(130,110,40,20);
		getContentPane().add(s);
	    s.setBounds(150,110,50,20);
	    //getContentPane().add(s1);
		//s1.setBounds(200,110,40,20);
		getContentPane().add(a);
		a.setBounds(220,110,50,20);
		//getContentPane().add(a1);
		//a1.setBounds(270,110,40,20);
		getContentPane().add(d);
		d.setBounds(280,110,50,20);
		//getContentPane().add(d1);
		//d1.setBounds(340,110,40,20);
		getContentPane().add(ttt);
		ttt.setBounds(10,140,370,30);
		getContentPane().add(ib2);
		ib2.setBounds(10,180,150,20);
		getContentPane().add(ta1);
		ta1.setBounds(190,180,100,20);
		getContentPane().add(b2);
	    b2.setBounds(305,180,72,20);
		getContentPane().add(ta2);
		ta2.setBounds(10,220,345,150);
		getContentPane().add(ib3);
		ib3.setBounds(390,80,120,40);
		getContentPane().add(ta3);
		ta3.setBounds(390,130,380,240);
		b.addActionListener(this);
		b2.addActionListener(this);
		}
		public static void main(String[] args)
			{
				NULL s=new NULL();
				s.show();
			}
			
		
	
	public void getrecord(String sno) throws SQLException
	{
		Connection con=null;
		try
		{
			Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
			
		}
		catch(ClassNotFoundException ex)
		{
			ttt.setText(ex.getMessage());
			System.exit(-1);
			
		}
		try
		{
			String url="jdbc:odbc:stuu";
			String user="sa";
			String password="";
			con=DriverManager.getConnection(url,user,password);
			//String 	SQLsc="SELECT * FROM sc ";
			String 	SQL="SELECT * FROM student"+ " where sno=? ";
			//Statement s =con.createStatement();
			PreparedStatement p=con.prepareStatement(SQL);
			p.setString(1,sno);
			ResultSet rs=p.executeQuery();
			//ResultSet rs1=s.executeQuery(SQLsc);
			ttt.setText("");
			
			while(rs.next())
			{
				ttt.append(rs.getString("sno")+"         ");
				ttt.append(rs.getString("sname")+"        ");
				ttt.append(rs.getString("ssex")+"               ");
				ttt.append(rs.getString("sage")+"               ");
				ttt.append(rs.getString("sdep")+"\n");
				
			}
		/*	while(rs1.next())
			{
				ta3.append(rs1.getString("cno")+"         ");
				ta3.append(rs1.getString("cname")+"         ");
				ta3.append(rs1.getString("cc")+"         ");
				ta3.append(rs1.getString("ca")+"         ");
			}*/
			rs.close();
			//rs1.close();
			p.close();
			//s.close();
		}catch(SQLException ex)
		{
			ttt.setText(ex.getMessage());
		}
		finally
		{
			con.close();
		}
		}
		public void getrecord11() throws SQLException
		{
			Connection con=null;
		try
		{
			Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
			
		}
		catch(ClassNotFoundException ex)
		{
			ta3.setText(ex.getMessage());
			System.exit(-1);
			
		}
		try
		{
			String url="jdbc:odbc:stuu";
			String user="sa";
			String password="";
			con=DriverManager.getConnection(url,user,password);
			String 	SQL="SELECT * FROM sc";
			Statement s =con.createStatement();
			//PreparedStatement p=con.prepareStatement(SQL);
			//p.setString(1,sno);
			ResultSet rs=s.executeQuery(SQL);
			//ResultSet rs1=s.executeQuery(SQLsc);
			//tfde.setText("");
			
			while(rs.next())
			{
				ta3.append(rs.getString("cno")+"         ");
				ta3.append(rs.getString("cname")+"        ");
				ta3.append(rs.getString("cc")+"               ");
				ta3.append(rs.getString("ca")+"               " + "\n");
				
			}
		
			rs.close();
			//rs1.close();
			//p.close();
			s.close();
		}catch(SQLException ex)
		{
			ta3.setText(ex.getMessage());
		}
		finally
		{
			con.close();
		}
		}
		public void getrecord1(String cno) throws SQLException
		{
			Connection con=null;
		try
		{
			Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
			
		}
		catch(ClassNotFoundException ex)
		{
			ta2.setText(ex.getMessage());
			System.exit(-1);
			
		}
		try
		{
			String url="jdbc:odbc:stuu";
			String user="sa";
			String password="";
			con=DriverManager.getConnection(url,user,password);
			String 	SQL="SELECT * FROM sc " + " where cno=? ";
			PreparedStatement p=con.prepareStatement(SQL);
			p.setString(1,cno);
			ResultSet rs=p.executeQuery();
			ta1.setText("");
			
			while(rs.next())
			{
				ta2.append(rs.getString("cno")+"         ");
				ta2.append(rs.getString("cname")+"        ");
				ta2.append(rs.getString("cc")+"               ");
				ta2.append(rs.getString("ca")+"               " + "\n");
				
			}
		
			rs.close();
			
			p.close();
			
		}catch(SQLException ex)
		{
			ta2.setText(ex.getMessage());
		}
		finally
		{
			con.close();
		}	
		}
		public void actionPerformed(ActionEvent e)
	{
		if (e.getSource()==b)
		{
			String ss=tfde.getText();
			try
			{
				getrecord(ss);
			}catch(SQLException ex)
		{
			ttt.setText(ex.getMessage());
		}
			
		}
		
		else if (e.getSource()==b2)
		{
		
		String ss1=ta1.getText();
			try
			{
				getrecord1(ss1);
			}catch(SQLException ex)
		{
			ta2.setText(ex.getMessage());
		}
		}
		
	}
	
			
			
			
			
}