修改成绩.java

经过调查分析

/*
 * 修改成绩.java
 *
 * Created on 2008年10月10日, 上午10:14
 */

package javaapplication1;
import java.sql.*;
import java.util.*;
import java.awt.*;
import javax.swing.*;
/**
 *
 * @author  mis06
 */
public class 修改成绩 extends javax.swing.JPanel {
    
    /** Creates new form 修改成绩 */
    public 修改成绩() {
        initComponents();
    }
    
    /** This method is called from within the constructor to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
     */
    // <editor-fold defaultstate="collapsed" desc=" Generated Code ">//GEN-BEGIN:initComponents
    private void initComponents() {
        jLabel1 = new javax.swing.JLabel();
        jTextField1 = new javax.swing.JTextField();
        jLabel2 = new javax.swing.JLabel();
        jTextField2 = new javax.swing.JTextField();
        jLabel3 = new javax.swing.JLabel();
        jTextField3 = new javax.swing.JTextField();
        jButton1 = new javax.swing.JButton();
        jButton3 = new javax.swing.JButton();

        jLabel1.setText("\u5b66\u53f7");

        jLabel2.setText("\u8bfe\u7a0b\u53f7");

        jLabel3.setText("\u6210\u7ee9");

        jButton1.setText("\u4fee\u6539");
        jButton1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton1ActionPerformed(evt);
            }
        });

        jButton3.setText("\u67e5\u770b\u6210\u7ee9");
        jButton3.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton3ActionPerformed(evt);
            }
        });

        org.jdesktop.layout.GroupLayout layout = new org.jdesktop.layout.GroupLayout(this);
        this.setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
            .add(layout.createSequentialGroup()
                .add(19, 19, 19)
                .add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.TRAILING)
                    .add(jButton3)
                    .add(layout.createSequentialGroup()
                        .add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
                            .add(jLabel1)
                            .add(jLabel2)
                            .add(jLabel3))
                        .add(9, 9, 9)
                        .add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING, false)
                            .add(jTextField3)
                            .add(jTextField2)
                            .add(jTextField1, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, 87, Short.MAX_VALUE))
                        .add(43, 43, 43)
                        .add(jButton1)))
                .addContainerGap(149, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
            .add(layout.createSequentialGroup()
                .add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
                    .add(layout.createSequentialGroup()
                        .add(27, 27, 27)
                        .add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.BASELINE)
                            .add(jLabel1)
                            .add(jTextField1, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE))
                        .add(31, 31, 31)
                        .add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.BASELINE)
                            .add(jLabel2)
                            .add(jTextField2, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)))
                    .add(layout.createSequentialGroup()
                        .add(54, 54, 54)
                        .add(jButton3)))
                .add(37, 37, 37)
                .add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.BASELINE)
                    .add(jLabel3)
                    .add(jTextField3, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
                    .add(jButton1))
                .addContainerGap(142, Short.MAX_VALUE))
        );
    }// </editor-fold>//GEN-END:initComponents

    private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jButton3ActionPerformed
   
    Statement statement;

        try{
            Connect con = new Connect();
            statement= con.con.createStatement();
            
           String studentNumber=jTextField1.getText();
            String courseNumber=jTextField2.getText();
            String score0 =null;
            
            String sql1="select 成绩 from 成绩 where 学号='"+studentNumber+"' AND 课程号='"+courseNumber+"'";
            ResultSet resultSet=statement.executeQuery(sql1);
            ResultSetMetaData metaData=resultSet.getMetaData();
           int numberOfColumns=metaData.getColumnCount();
           
             while(resultSet.next())
            {  
                for(int i=1;i<=numberOfColumns;i++)
                  score0=resultSet.getObject(i).toString();
            }
       
             jTextField3.setText(score0);
      
    }
    catch(SQLException sqlException){
        JOptionPane.showMessageDialog(null,sqlException.getMessage(),"Database Error",JOptionPane.ERROR_MESSAGE);
        System.exit(1);}
   catch(ClassNotFoundException classNotFound){
       JOptionPane.showMessageDialog(null,classNotFound.getMessage(),"Driver Not Found",JOptionPane.ERROR_MESSAGE);
        System.exit(1); }// TODO add your handling code here:
    }//GEN-LAST:event_jButton3ActionPerformed

    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jButton1ActionPerformed
    

    Statement statement;

        try{
            Connect con = new Connect();
            statement= con.con.createStatement();
            
           String studentNumber=jTextField1.getText();
            String courseNumber=jTextField2.getText();
            String score0 =jTextField3.getText();
            

            
            String sql2="update 成绩 set 成绩="+score0+" where 学号='"+studentNumber+"' AND 课程号='"+courseNumber+"'";
            int reg= statement.executeUpdate(sql2);
           
            if(reg==1)    
            JOptionPane.showMessageDialog(null,"成功修改成绩");
            else
            JOptionPane.showMessageDialog(null,"不存在该学生或课程！");
            
       }
    catch(SQLException sqlException){
        JOptionPane.showMessageDialog(null,sqlException.getMessage(),"Database Error",JOptionPane.ERROR_MESSAGE);
        System.exit(1);}
   catch(ClassNotFoundException classNotFound){
       JOptionPane.showMessageDialog(null,classNotFound.getMessage(),"Driver Not Found",JOptionPane.ERROR_MESSAGE);
        System.exit(1); }// TODO add your handling code here:
    }//GEN-LAST:event_jButton1ActionPerformed
    
    
    // Variables declaration - do not modify//GEN-BEGIN:variables
    private javax.swing.JButton jButton1;
    private javax.swing.JButton jButton3;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JLabel jLabel3;
    private javax.swing.JTextField jTextField1;
    private javax.swing.JTextField jTextField2;
    private javax.swing.JTextField jTextField3;
    // End of variables declaration//GEN-END:variables
    
}