stuclass.java

学生成绩管理系统

/*
 * Stuclass.java
 *
 * Created on 2007年11月17日, 上午11:25
 */

package javaapplication1;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import javax.swing.JOptionPane;

/**
 *
 * @author  mis05
 */
public class Stuclass extends javax.swing.JPanel {
    
    /** Creates new form Stuclass */
    public Stuclass() {
        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() {
        jButton1 = new javax.swing.JButton();
        jLabel1 = new javax.swing.JLabel();
        jTextField1 = new javax.swing.JTextField();
        jLabel2 = new javax.swing.JLabel();
        jTextField2 = new javax.swing.JTextField();

        jButton1.setFont(new java.awt.Font("宋体", 0, 14));
        jButton1.setText("\u6dfb\u52a0");
        jButton1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                addclass(evt);
            }
        });

        jLabel1.setFont(new java.awt.Font("宋体", 1, 18));
        jLabel1.setText("\u8bfe\u7a0b\u7f16\u53f7");

        jLabel2.setFont(new java.awt.Font("宋体", 1, 18));
        jLabel2.setText("\u5b66\u751f\u7f16\u53f7");

        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(63, 63, 63)
                .add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.TRAILING)
                    .add(jLabel2)
                    .add(jLabel1))
                .add(30, 30, 30)
                .add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
                    .add(jTextField2, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, 93, Short.MAX_VALUE)
                    .add(jTextField1, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, 93, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE))
                .add(138, 138, 138))
            .add(layout.createSequentialGroup()
                .add(121, 121, 121)
                .add(jButton1, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, 66, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(213, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
            .add(layout.createSequentialGroup()
                .add(69, 69, 69)
                .add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.BASELINE)
                    .add(jLabel2)
                    .add(jTextField2, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, 28, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE))
                .add(33, 33, 33)
                .add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.BASELINE)
                    .add(jTextField1, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, 28, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
                    .add(jLabel1))
                .add(32, 32, 32)
                .add(jButton1, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, 31, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(78, Short.MAX_VALUE))
        );
    }// </editor-fold>//GEN-END:initComponents

    private void addclass(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_addclass
Statement sql;

        try{
            Conect conect = new Conect();
            sql = conect.dbConn.createStatement();
            
            String string=null;
            String string1=null;
            int temp = 0;
            String number = jTextField2.getText();
            String classNo = jTextField1.getText();
            
            if( number.equals("") )
            {
                JOptionPane.showMessageDialog(null,"清输入选课学生编号","错误",JOptionPane.ERROR_MESSAGE);
            }
            
            if( classNo.equals("") )
            {
                JOptionPane.showMessageDialog(null,"清输入选课课程号","错误",JOptionPane.ERROR_MESSAGE);
            }
            else
            {
                ResultSet rs = sql.executeQuery("select 学生编号 from 学生 where 学生编号 = '"+ number +"'");
                if( rs.next() ) temp ++;
                else JOptionPane.showMessageDialog(null,"不存在此学生","错误",JOptionPane.ERROR_MESSAGE);
                
                
                rs = sql.executeQuery("select 课程编号 from 课程 where 课程编号 = '"+ classNo +"'");
                if( rs.next() ) temp ++;
                else JOptionPane.showMessageDialog(null,"不存在此课程","错误",JOptionPane.ERROR_MESSAGE);
            
                rs = sql.executeQuery("select 学生编号,课程编号 from 选课 where 课程编号 = '"+ classNo +"' and 学生编号 = '"+ number +"'");
                if( rs.next() ) JOptionPane.showMessageDialog(null,"你已经选择了此课程","错误",JOptionPane.ERROR_MESSAGE);
                else temp ++;
                
                StringBuffer buffer1 = new StringBuffer();
                StringBuffer buffer2 = new StringBuffer();
                String peopleCount = null;
                String peopleMax = null;
                rs = sql.executeQuery("select 已选人数 from 课程 where 课程编号 = '"+classNo+"'");
                rs.next();
                buffer1.append( rs.getObject(1) );
                peopleCount = buffer1.toString();
                
                rs = sql.executeQuery("select 容量 from 课程 where 课程编号 ='"+classNo+"'");
                rs.next();
                buffer2.append( rs.getObject(1) );
                peopleMax = buffer2.toString();
                
                if( peopleMax.equals( peopleCount ) )
                {
                    JOptionPane.showMessageDialog(null,"此课程人数已满","失败",JOptionPane.INFORMATION_MESSAGE);
                }
                else
                {
                    temp ++;
                }
            
                if( temp == 4 )
                {
                    rs = sql.executeQuery("select 课程名称 from 课程 where 课程编号='"+number+"'");
                    while( rs.next() )
                    {
                        string1 = (String) rs.getObject(1);
                    }
                    
                    int reg;
                    reg = sql.executeUpdate("insert into 选课 (学生编号,课程编号,课程名称) values('"+number+"','"+classNo+"','"+string1+"')");
                    reg = sql.executeUpdate("UPDATE 课程 SET 已选人数 = 已选人数+1 WHERE 课程编号 = '"+classNo+"'");                                       
                    
                    JOptionPane.showMessageDialog(null,"选课成功","成功",JOptionPane.INFORMATION_MESSAGE);
                }
            }
            

}
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_addclass
    
    
    // Variables declaration - do not modify//GEN-BEGIN:variables
    private javax.swing.JButton jButton1;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JTextField jTextField1;
    private javax.swing.JTextField jTextField2;
    // End of variables declaration//GEN-END:variables
    
}