add.java

管理学生信息

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
import java.sql.*;
class Add extends JFrame implements ActionListener//添加成绩
{
	Choice text1,text2;
	JLabel label1,label2,label3;
	JButton ok,cancel;
	JTextField text3;
	Add(){
		super("添加成绩");
		setSize(500,500);
		setLayout(null);
		setVisible(true);
		Connection con=null;
		Statement sm=null;
		String command=null;
		ResultSet rs=null;

		setBackground(Color.green);
		label1=new JLabel("*学号:");
		label2=new JLabel("*课程名:");
		label3=new JLabel("成绩:");
		text1=new Choice();
		try{
			try{
				Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
				con=DriverManager.getConnection("jdbc:odbc:student");
			}catch(Exception mm){System.out.println(mm.getMessage());}
			sm=con.createStatement();
			command="select sno from st order by sno";
			rs=sm.executeQuery(command);
			while(rs.next())
				text1.add(rs.getString("sno"));
			rs.close();
		}catch(SQLException k){System.out.println(k.getMessage());}

		text2=new Choice();
		try{
			command="select cname from ch order by cno";
			rs=sm.executeQuery(command);
			while(rs.next())
				text2.add(rs.getString(1));
			rs.close();
			sm.close();
			con.close();
		}catch(SQLException ek){System.out.println(ek.getMessage());}
		add(label1);add(text1);
		add(label2);add(text2);

		text3=new JTextField();
		add(label3);add(text3);

		label1.setBounds(50,50,110,30);
		text1.setBounds(180,50,80,30);
		label2.setBounds(50,150,110,30);
		text2.setBounds(180,150,80,30);
		label3.setBounds(50,250,110,30);
		text3.setBounds(180,250,80,30);

		ok=new JButton("确定");
		cancel=new JButton("取消");
		add(cancel);
		add(ok);
		ok.setBounds(40,350,80,20);
		cancel.setBounds(170,350,80,20);
		cancel.addActionListener(this);
		ok.addActionListener(this);
		setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
	}
	public void actionPerformed(ActionEvent e)
	{
		if(e.getSource()==ok)
		{
			Connection con=null;
			Statement sm=null;
			String command=null;
			try{
				//DriverManager.registerDriver(new com.microsoft.jdbc.sqlserver.SQLServerDriver());
				Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
				con=DriverManager.getConnection("jdbc:odbc:student");
		}catch(Exception ex){
			System.out.println(ex.getMessage());
			return;
		}
		try{
			sm=con.createStatement();
			String str1="'"+text1.getSelectedItem()+"'";
			String str2="'"+text2.getSelectedItem()+"'";
			command="select sno,cno from sc where sno="+str1+" and cno in( select cno from ch where cname="+str2+")";
			ResultSet re=sm.executeQuery(command);
			if(re.next())
			{
				command="update sc set grade="+Float.parseFloat(text3.getText())+" where sno="+str1+" and cno='"+re.getString(2)+"'";
				sm.executeUpdate(command);
				JOptionPane.showMessageDialog(this,"插入成功","插入成功",JOptionPane.INFORMATION_MESSAGE);
			}
			else{
				JOptionPane.showMessageDialog(this,"该记录不存在!","warring",JOptionPane.WARNING_MESSAGE);	
			}
		}catch(Exception ey){
				JOptionPane.showMessageDialog(this,"请填入成绩","warring",JOptionPane.WARNING_MESSAGE);
		}
		try{
			sm.close();
			con.close();
			dispose();
		}catch(Exception ez){}
		setVisible(false);
		}
		else
		{
			dispose();
			setVisible(false);
		}
	}
}