coursegrade.java

综合测评管理系统——完成班级的综合测评工作

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

public class CourseGrade extends JFrame{
	private Connection dbConn;
	private PreparedStatement ps;
	private ResultSet rs;
	private ResultSetMetaData rsMetaData;
	
	//GUI变量定义
	private JTable table;
	private JTextArea inputQuery; 
	private JButton submitQuery;
	Container c=getContentPane();
	
	public CourseGrade() 
	{
		//Form的标题 
		super("课程管理"); 
		
		final String dbURL="jdbc:sqlserver://localhost:1433; DatabaseName=sample"; 
		final String username="sa"; 
		final String password="2005"; 
		//加载驱动程序以连接数据库
		try{
			Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver"); 
			dbConn=DriverManager.getConnection(dbURL,username,password);
		}catch(ClassNotFoundException cnfex){
			System.err.println("装载 JDBC/ODBC 驱动程序失败。");
			cnfex.printStackTrace();
			System.exit(1); // terminate program
		}catch(SQLException sqlex){
			System.err.println( "无法连接数据库" );
			sqlex.printStackTrace();
			System.exit(1); // terminate program
		}
		
		//如果数据库连接成功，则建立GUI
		//Button事件
		
		JPanel topPanel = new JPanel();
		GridBagLayout lay=new GridBagLayout();
		GridBagConstraints constraints=new GridBagConstraints();
		topPanel.setLayout(lay);
		//Button ok_button=new Button("确定");
	  JButton modify_button=new JButton("修改");
	  JButton exit_button=new JButton("退出");
	  JButton add_button=new JButton("添加");
	  JButton delete_button=new JButton("删除");
	  
	  JLabel studentno_label=new JLabel("学号: ");
	  final JTextField studentno_textfield=new JTextField();
	  JLabel coursename_label=new JLabel("课程名: ");
	  final JComboBox coursename_combobox=new JComboBox();
	  JLabel grade_label=new JLabel("课程成绩: ");
	  final JTextField grade_textfield=new JTextField();
	  String[] temp={"2006-2007","2007-2008","2008-2009","2009-2010"};
	  JLabel acadyear_label=new JLabel("学年: ");
	  final JComboBox acadyear_combobox=new JComboBox(temp);
	   
	  JLabel userinfo_label=new JLabel("课程信息:");
	  
	  //初始化JComboBox
	  coursename_combobox.setEditable(true); 
	  try{
			//执行SQL语句 
			String query ="select * from course";
			ps=dbConn.prepareStatement(query);
			rs=ps.executeQuery();
			while(rs.next()){
				coursename_combobox.addItem(rs.getString("cname"));
			}
		}catch(SQLException sqlex){
			sqlex.printStackTrace();
		}
			
	  constraints.anchor=GridBagConstraints.CENTER;
	     
	  constraints.gridx=0;
	  constraints.gridy=0;
	  constraints.weightx=1;
	  constraints.weighty=1;
	  constraints.gridwidth=1;
	  constraints.gridheight=1;
	  constraints.fill=GridBagConstraints.NONE;
	  constraints.anchor=GridBagConstraints.EAST;
	  topPanel.add(studentno_label,constraints);
	      
	  constraints.gridx=1;
	  constraints.gridy=0;
	  constraints.weightx=1;
	  constraints.weighty=2;
	  constraints.gridwidth=1;
	  constraints.gridheight=1;
	  constraints.fill=GridBagConstraints.BOTH;
	  constraints.anchor=GridBagConstraints.CENTER;
	  topPanel.add(studentno_textfield,constraints);
	     
	  constraints.gridx=2;
	  constraints.gridy=0;
	  constraints.weightx=1;
	  constraints.weighty=1;
	  constraints.gridwidth=1;
	  constraints.gridheight=1;
	  constraints.fill=GridBagConstraints.NONE;
	  constraints.anchor=GridBagConstraints.CENTER;
	  topPanel.add(modify_button,constraints);
	           
	  constraints.gridx=0;
	  constraints.gridy=1;
	  constraints.weightx=1;
	  constraints.weighty=1;
	  constraints.gridwidth=1;
	  constraints.gridheight=1;
	  constraints.fill=GridBagConstraints.NONE;
	  constraints.anchor=GridBagConstraints.EAST;
	  topPanel.add(coursename_label,constraints);
	     
	  constraints.gridx=1;
	  constraints.gridy=1;
	  constraints.weightx=1;
	  constraints.weighty=2;
	  constraints.gridwidth=1;
	  constraints.gridheight=1;
	  constraints.fill=GridBagConstraints.BOTH;
	  constraints.anchor=GridBagConstraints.CENTER;
	  topPanel.add(coursename_combobox,constraints);
	  
	  constraints.gridx=2;
	  constraints.gridy=1;
	  constraints.weightx=1;
	  constraints.weighty=2;
	  constraints.gridwidth=1;
	  constraints.gridheight=1;
	  constraints.fill=GridBagConstraints.NONE;
	  constraints.anchor=GridBagConstraints.CENTER;
	  topPanel.add(exit_button,constraints);
	  
	  constraints.gridx=0;
	  constraints.gridy=2;
	  constraints.weightx=1;
	  constraints.weighty=1;
	  constraints.gridwidth=1;
	  constraints.gridheight=1;
	  constraints.fill=GridBagConstraints.NONE;
	  constraints.anchor=GridBagConstraints.EAST;
	  topPanel.add(grade_label,constraints);
	     
	  constraints.gridx=1;
	  constraints.gridy=2;
	  constraints.weightx=1;
	  constraints.weighty=2;
	  constraints.gridwidth=1;
	  constraints.gridheight=1;
	  constraints.fill=GridBagConstraints.BOTH;
	  constraints.anchor=GridBagConstraints.CENTER;
	  topPanel.add(grade_textfield,constraints);
	  
	  constraints.gridx=0;
	  constraints.gridy=3;
	  constraints.weightx=1;
	  constraints.weighty=1;
	  constraints.gridwidth=1;
	  constraints.gridheight=1;
	  constraints.fill=GridBagConstraints.NONE;
	  constraints.anchor=GridBagConstraints.EAST;
	  topPanel.add(acadyear_label,constraints);
	     
	  constraints.gridx=1;
	  constraints.gridy=3;
	  constraints.weightx=1;
	  constraints.weighty=2;
	  constraints.gridwidth=1;
	  constraints.gridheight=1;
	  constraints.fill=GridBagConstraints.BOTH;
	  constraints.anchor=GridBagConstraints.CENTER;
	  topPanel.add(acadyear_combobox,constraints);
	      
	  constraints.gridx=0;
	  constraints.gridy=4;
	  constraints.weightx=1;
	  constraints.weighty=1;
	  constraints.gridwidth=2;
	  constraints.gridheight=1;
	  constraints.fill=GridBagConstraints.NONE;
	  constraints.anchor=GridBagConstraints.CENTER;
	  topPanel.add(add_button,constraints);
	      
	  constraints.gridx=1;
	  constraints.gridy=4;
	  constraints.weightx=1;
	  constraints.weighty=1;
	  constraints.gridwidth=2;
	  constraints.gridheight=1;
	  constraints.fill=GridBagConstraints.NONE;
	  constraints.anchor=GridBagConstraints.CENTER;
	  topPanel.add(delete_button,constraints);
	  
	  //按钮的单击事件处理
	  
	  /*ok_button.addActionListener(new ActionListener(){
	  	public void actionPerformed(ActionEvent e){
	  		
	  	}
	  });*/
	  
	  modify_button.addActionListener(new ActionListener(){
	  	public void actionPerformed(ActionEvent e){
	  		String[] temp={"","",""};
	  		temp[0]=(String)coursename_combobox.getSelectedItem();
	  		temp[1]=studentno_textfield.getText();
	  		temp[2]=grade_textfield.getText();
	  		if(temp[0].equals("")||temp[1].equals("")||temp[2].equals("")){
	  			JOptionPane.showMessageDialog(new JFrame(),"记录不能为空","警告",JOptionPane.WARNING_MESSAGE);
	  		}else{
	  		  try{
	  		  	//判断课程是否存在
	  		    dbConn=DriverManager.getConnection(dbURL,username,password);
	  				String selectStr="select cno from course where cname=? and academic_year=?";
	  				ps=dbConn.prepareStatement(selectStr);
	  				ps.setString(1,(String)coursename_combobox.getSelectedItem());
	  				ps.setString(2,(String)acadyear_combobox.getSelectedItem());
	  				rs=ps.executeQuery();
	  				if(!rs.next()){