学生成绩管理系统课程设计
- 需求分析
-
- E-R图
-
- 逻辑关系
- 物理设计和实施
-
- 创建包、Add、Del、Update、Sel
- idea链接数据库
-
- 简单SQL语句
-
- 答辩
需求分析
1 信息需求
对学校而言，学生成绩管理是管理工作中重要的一环，但是高校学生的成绩管理工作量大、繁杂，人工处理非常困难。因此，借助于强大计算机的处理能力，能够把人从繁重的成绩管理工作中解脱出来，并且更加准确、安全、清晰的管理环境。
2 功能需求
能够进行数据库的数据定义、数据操纵、数据控制等处理功能。具体功能应包括：可提供课程安排、课程成绩数据的添加、插入、删除、更新、查询，学生及教职工基本信息查询的功能。
3 安全性与完整性要求
对于学生成绩管理系统数据库来讲，由于其主要数据是学生成绩，只能由本人以及所教老师及教务处知道，因此做好数据安全性是重中之重。另外，要求所有在校学生的信息都要录入其中，并且要设计好个别情况。
E-R图
一位学生会被多位老师教导，一位老师会教导多位学生，所有学生与教师之间是多对多（m:n）的关系；
一位学生可能会选修多门课程，一门课程会被多位学生选修，所以学生与课程之间是多对多（m:n）的关系；
一位学生会有多项成绩（具体指某学生一门课程的分数），一项成绩仅被一位学生拥有，所以学生与成绩是一对多（1:n）的关系；
一位教师会讲授多门课程，一门课程会被一位教师讲授，所以教师与课程的关系是一对多（1:n）的关系；
一门课程拥有多项成绩，一项成绩仅被一门课程拥有，所以课程与成绩的关系是一对多（1:n）的关系；
学生（学号、姓名、班级、性别、专业、出生日期、学分）；
老师（教师编号、姓名、学院）；
课程（课程编号、教师编号、课程名称、课程学分）；
成绩（学号、课程编号、分数）；
逻辑关系
根据题目要求可以简化成三个表：
1.student 表：学号（sno）、姓名（sname）、性别（ssex）、专业（sdept），此为联系“student表”所对应的关系模式，学号为该关系的候选码，满足第三范式。
2.course表：课程编号（cno）、教师（cteacher）、课程名称（cname）、先修课课程号(cpno)、学分（ccredit），此为联系“course表”所对应的关系模式，课程编号和教师编号为该关系的候选码，满足第三范式。
3.sc表：学号（sno）、课程编号（cno）、分数（grade），此为联系“sc表”所对应的关系模式，学号和课程编号为该关系的候选码，满足第三范式。
物理设计和实施
创建course表
属性依次为：课程号、课程名、先修课课程号、学分、教师
主键为课程号
创建student表
属性依次为：学号、姓名、性别、年龄、所在系系名
主键为学号
sdept char(15) null勾选
注意学号不要写重复，会报错
创建sc表，表示选课关系
属性依次为学号、课程号、分数
主键为学号、课程号
数据库链接到idea
idea没有database的下载：
File+settings+editor+plugins+database navigator+apply+ok
出现感叹号：进connection+properties+serverTimezone+Asia/Shanghai+test connection
创建包、Add、Del、Update、Sel
主代码再最后面
AddC
/*
AddC
*/
package sc;
import java.awt.*;
import javax.swing.*;
import java.sql.*;
import java.awt.event.*;
public class AddC extends JPanel implements ActionListener{
JTextField 课程号,课程名,先修课课程号,学分;
JButton 录入;
public AddC(){
try {UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());}
catch(Exception e){System.err.println("不能设置外观: "+e);}
课程号=new JTextField(12);
课程名=new JTextField(12);
先修课课程号=new JTextField(12);
学分=new JTextField(12);
录入=new JButton("录入");
录入.addActionListener(this);
Box box1=Box.createHorizontalBox();//横放box
Box box2=Box.createHorizontalBox();
Box box3=Box.createHorizontalBox();
Box box4=Box.createHorizontalBox();
Box box5=Box.createHorizontalBox();
Box box6=Box.createHorizontalBox();
box1.add(new JLabel("课程号:"));
box1.add(课程号);
box2.add(new JLabel("课程名:"));
box2.add(课程名);
box3.add(new JLabel("先修课课程号:"));
box3.add(先修课课程号);
box4.add(new JLabel("学分:"));
box4.add(学分);
box6.add(录入);
Box boxH=Box.createVerticalBox();//竖放box
boxH.add(box1);
boxH.add(box2);
boxH.add(box3);
boxH.add(box4);
boxH.add(box5);
boxH.add(box6);
boxH.add(Box.createVerticalGlue());
JPanel messPanel=new JPanel();
messPanel.add(boxH);
setLayout(new BorderLayout());
add(messPanel,BorderLayout.CENTER);
validate();
}
public void actionPerformed(ActionEvent c){
Object obj=c.getSource();
if(obj==录入){
if(课程号.getText().equals("")||课程名.getText().equals("")||先修课课程号.getText().equals("")||学分.getText().equals("")){
JOptionPane.showMessageDialog(this,"学生信息请填满再录入！" );
}
Statement stmt=null;
ResultSet rs=null,rs1=null;
String sql,sql1;
sql1="select * from Course where Cno='"+课程号.getText()+"'";
sql="insert into Course values('"+课程号.getText()+"','"+课程名.getText()+"','"+先修课课程号.getText()+"','"+学分.getText()+"')";
try{
Connection dbConn1=CONN();
stmt=(Statement)dbConn1.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
rs1=stmt.executeQuery(sql1);
if(rs1.next()){JOptionPane.showMessageDialog(this,"该课号以存在，无法添加");}
else{
stmt.executeUpdate(sql);
JOptionPane.showMessageDialog(this,"添加成功");
}
rs1.close();
stmt.close();
}
catch(SQLException e){
System.out.print("SQL Exception occur.Message is:"+e.getMessage());
}
}
}
public static Connection CONN(){
String driverName = "com.microsoft.sqlserver.jdbc.SQLServerDriver"; //加载JDBC驱动
String dbURL = "jdbc:sqlserver://主机名:1433; DatabaseName=数据库名"; //连接服务器和数据库test
String userName = "sa"; //默认用户名
String userPwd = "密码"; //密码
Connection dbConn=null;
try {
Class.forName(driverName);
dbConn = DriverManager.getConnection(dbURL, userName, userPwd);
System.out.println("Connection Successful!"); //如果连接成功 控制台输出Connection Successful!
} catch (Exception e) {
e.printStackTrace();
}
return dbConn;
}
}
AddS
/*
AddS
*/
package sc;
import java.awt.*;
import javax.swing.*;
import java.sql.*;
import java.awt.event.*;
public class AddS extends JPanel implements ActionListener{
JTextField 学号,姓名,性别,年龄,所在系系名;
JButton 录入;
public AddS(){
try {UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());}
catch(Exception e){System.err.println("不能设置外观: "+e);}
学号=new JTextField(12);
姓名=new JTextField(12);
性别=new JTextField(12);
年龄=new JTextField(12);
所在系系名=new JTextField(12);
录入=new JButton("录入");
录入.addActionListener(this);
Box box1=Box.createHorizontalBox();//横放box
Box box2=Box.createHorizontalBox();
Box box3=Box.createHorizontalBox();
Box box4=Box.createHorizontalBox();
Box box5=Box.createHorizontalBox();
Box box6=Box.createHorizontalBox();
box1.add(new JLabel("学号:"/*,JLabel.CENTER*/));
box1.add(学号);
box2.add(new JLabel("姓名:"/*,JLabel.CENTER*/));
box2.add(姓名);
box3.add(new JLabel("性别:"/*,JLabel.CENTER*/));
box3.add(性别);
box4.add(new JLabel("年龄:"/*,JLabel.CENTER*/));
box4.add(年龄);
box5.add(new JLabel("所在系系名:"/*,JLabel.CENTER*/));
box5.add(所在系系名);
box6.add(录入);
Box boxH=Box.createVerticalBox();//竖放box
boxH.add(box1);
boxH.add(box2);
boxH.add(box3);
boxH.add(box4);
boxH.add(box5);
boxH.add(box6);
boxH.add(Box.createVerticalGlue());
JPanel messPanel=new JPanel();
messPanel.add(boxH);
setLayout(new BorderLayout());
add(messPanel,BorderLayout.CENTER);
validate();
}
public void actionPerformed(ActionEvent c){
Object obj=c.getSource();
if(obj==录入){
if(学号.getText().equals("")||姓名.getText().equals("")||性别.getText().equals("")||年龄.getText().equals("")||所在系系名.getText().equals("")){
JOptionPane.showMessageDialog(this,"学生信息请填满再录入！" );
}
Statement stmt=null;
ResultSet rs1=null;
String sql,sql1;
sql1="select * from Student where Sno='"+学号.getText()+"'";
sql="insert into Student values('"+学号.getText()+"','"+姓名.getText()+"','"+性别.getText()+"','"+年龄.getText()+"','"+所在系系名.getText()+"')";
try{
Connection dbConn1=CONN();
stmt=(Statement)dbConn1.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
rs1=stmt.executeQuery(sql1);
if(rs1.next()){JOptionPane.showMessageDialog(this,"该学号已经存在，无法添加");}
else{
stmt.executeUpdate(sql);
JOptionPane.showMessageDialog(this,"添加成功");
}
rs1.close();
stmt.close();
}
catch(SQLException e){
System.out.print("SQL Exception occur.Message is:"+e.getMessage());
}
}
}
public static Connection CONN(){
String driverName = "com.microsoft.sqlserver.jdbc.SQLServerDriver"; //加载JDBC驱动
String dbURL = "jdbc:sqlserver://主机名:1433; DatabaseName=数据库名"; //连接服务器和数据库test
String userName = "sa"; //默认用户名
String userPwd = "密码"; //密码
Connection dbConn=null;
try {
Class.forName(driverName);
dbConn = DriverManager.getConnection(dbURL, userName, userPwd);
System.out.println("Connection Successful!"); //如果连接成功 控制台输出Connection Successful!
} catch (Exception e) {
e.printStackTrace();
}
return dbConn;
}
}
AddSC
/*
AddSC
*/
package sc;
import java.awt.*;
import javax.swing.*;
import java.sql.*;
import java.util.*;
import javax.swing.filechooser.*;
import java.io.*;
import java.awt.event.*;
public class AddSC extends JPanel implements ActionListener{
JTextField 课程号,学号,成绩;
JButton 录入;
public AddSC(){
try {UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());}
catch(Exception e){System.err.println("不能设置外观: "+e);}
课程号=new JTextField(12);
学号=new JTextField(12);
成绩=new JTextField(12);
录入=new JButton("录入");
录入.addActionListener(this);
Box box1=Box.createHorizontalBox();//横放box
Box box2=Box.createHorizontalBox();
Box box3=Box.createHorizontalBox();
Box box4=Box.createHorizontalBox();
box1.add(new JLabel("课号:"));
box1.add(课程号);
box2.add(new JLabel("学号:"));
box2.add(学号);
box3.add(new JLabel("成绩:"));
box3.add(成绩);
box4.add(录入);
Box boxH=Box.createVerticalBox();//竖放box
boxH.add(box1);
boxH.add(box2);
boxH.add(box3);
boxH.add(box4);
boxH.add(Box.createVerticalGlue());
JPanel messPanel=new JPanel();
messPanel.add(boxH);
setLayout(new BorderLayout());
add(messPanel,BorderLayout.CENTER);
validate();
}
public void actionPerformed(ActionEvent c){
Object obj=c.getSource();
if(obj==录入){
if(课程号.getText().equals("")||学号.getText().equals("")){
JOptionPane.showMessageDialog(this,"填写课号与学号才能录入！" );
}
else
{
Statement stmt=null;
ResultSet rs=null,rs1=null,rsC=null,rsS=null;
String sql,sql1,sqlS,sqlC;
sqlC="select * from Course where Cno='"+课程号.getText()+"'";
sqlS="select * from Student where Sno='"+学号.getText()+"'";
sql1="select * from SC where Cno='"+课程号.getText()+"' and Sno='"+学号.getText()+"'";
sql="insert into SC values('"+学号.getText()+"','"+课程号.getText()+"','"+成绩.getText()+"')";
try{
Connection dbConn1=CONN();
stmt=(Statement)dbConn1.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
rsC=stmt.executeQuery(sqlC);
if(rsC.next()){
rsS=stmt.executeQuery(sqlS);
if(rsS.next()){
rs1=stmt.executeQuery(sql1);
if(rs1.next()){JOptionPane.showMessageDialog(this,"该学生以选该课程号，无法添加");}
else{
stmt.executeUpdate(sql);
JOptionPane.showMessageDialog(this,"添加成功");
}
rs1.close();
}
else{JOptionPane.showMessageDialog(this,"该学生不存在，无法添加");}
rsS.close();
}
else{JOptionPane.showMessageDialog(this,"该课程不存在，无法添加");}
rsC.close();
stmt.close();
}
catch(SQLException e){
System.out.print("SQL Exception occur.Message is:"+e.getMessage());
}
}
}
}
public static Connection CONN(){
String driverName = "com.microsoft.sqlserver.jdbc.SQLServerDriver"; //加载JDBC驱动
String dbURL = "jdbc:sqlserver://主机名:1433; DatabaseName=数据库名"; //连接服务器和数据库test
String userName = "sa"; //默认用户名
String userPwd = "密码"; //密码
Connection dbConn=null;
try {
Class.forName(driverName);
dbConn = DriverManager.getConnection(dbURL, userName, userPwd);
System.out.println("Connection Successful!"); //如果连接成功 控制台输出Connection Successful!
} catch (Exception e) {
e.printStackTrace();
}
return dbConn;
}
}
DelC
/*
DelC
*/
package sc;
import java.awt.*;
import java.awt.event.*;
import java.sql.*;
import javax.swing.*;
public class DelC extends JPanel implements ActionListener{
String save=null;
JTextField 课号1,课程号,课程名,先修课课程号,学分;
JButton 删除,查找;
public DelC(){
try {UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());}
catch(Exception e){System.err.println("不能设置外观: "+e);}
课号1=new JTextField(12);
课程号=new JTextField(12);
课程名=new JTextField(12);
先修课课程号=new JTextField(12);
学分=new JTextField(12);
删除=new JButton("删除");
查找=new JButton("查找");
Box box1=Box.createHorizontalBox();//横放box
Box box2=Box.createHorizontalBox();
Box box3=Box.createHorizontalBox();
Box box4=Box.createHorizontalBox();
Box box5=Box.createHorizontalBox();
Box box6=Box.createHorizontalBox();
Box box7=Box.createHorizontalBox();
box1.add(new JLabel("课程号:",JLabel.CENTER));
box1.add(课程号);
box2.add(new JLabel("课程名:",JLabel.CENTER));
box2.add(课程名);
box3.add(new JLabel("先修课课程号:",JLabel.CENTER));
box3.add(先修课课程号);
box4.add(new JLabel("学分:",JLabel.CENTER));
box4.add(学分);
box6.add(删除);
box7.add(new JLabel("课号:",JLabel.CENTER));
box7.add(课号1);
box7.add(查找);
Box boxH=Box.createVerticalBox();//竖放box
boxH.add(box1);
boxH.add(box2);
boxH.add(box3);
boxH.add(box4);
boxH.add(box5);
boxH.add(box6);
//boxH.add(box7);
boxH.add(Box.createVerticalGlue());
删除.addActionListener(this);
查找.addActionListener(this);
JPanel picPanel=new JPanel();
JPanel messPanel=new JPanel();
messPanel.add(box7);
picPanel.add(boxH);
setLayout(new BorderLayout());
JSplitPane splitV=new JSplitPane(JSplitPane.VERTICAL_SPLIT,messPanel,picPanel);//分割
add(splitV,BorderLayout.CENTER);
validate();
}
public void actionPerformed(ActionEvent e){
Object obj=e.getSource();
Statement stmt=null;
ResultSet rs=null,rs1=null;
String sql=null,sql1=null,sqlSC=null;
if(obj==查找){if(课号1.getText().equals(""))JOptionPane.showMessageDialog(this,"请填写查询的课号！" );
else{
sql1="select * from Course where Cno='"+课号1.getText()+"'";
try{
Connection dbConn1=CONN();
stmt=(Statement)dbConn1.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
rs1=stmt.executeQuery(sql1);
if(rs1.next()){课程号.setText(rs1.getString("Cno").trim());
课程名.setText(rs1.getString("Cname").trim());
先修课课程号.setText(rs1.getString("Cpno").trim());
学分.setText(rs1.getString("Ccredit").trim());
save=课号1.getText().trim();
}
else{JOptionPane.showMessageDialog(this,"没有这个课号的课程" );}
stmt.close();
rs1.close();
}catch(SQLException e1){
System.out.print("SQL Exception occur.Message is:"+e1.getMessage());
}
}
}
else{
if(obj==删除){if(save==null)JOptionPane.showMessageDialog(this,"还没查找需要修改的课程" );
else{sql="delete from Course where Cno='"+save+"'";
sqlSC="delete from SC where Cno='"+save+"'";
try{
Connection dbConn1=CONN();
stmt=(Statement)dbConn1.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
stmt.executeUpdate(sql);
stmt.executeUpdate(sqlSC);
save=null;
JOptionPane.showMessageDialog(this,"删除完成" );
课程号.setText("");
课程名.setText("");
先修课课程号.setText("");
学分.setText("");
stmt.close();
}catch(SQLException e1){
System.out.print("SQL Exception occur.Message is:"+e1.getMessage());
}
}
}
}
}
// 连接数据库方法
public static Connection CONN(){
String driverName = "com.microsoft.sqlserver.jdbc.SQLServerDriver"; //加载JDBC驱动
String dbURL = "jdbc:sqlserver://主机名:1433; DatabaseName=数据库名"; //连接服务器和数据库test
String userName = "sa"; //默认用户名
String userPwd = "密码"; //密码
Connection dbConn=null;
try {
Class.forName(driverName);
dbConn = DriverManager.getConnection(dbURL, userName, userPwd);
System.out.println("Connection Successful!"); //如果连接成功 控制台输出Connection Successful!
} catch (Exception e) {
e.printStackTrace();
}
return dbConn;
}
}
DelS
/*
DelS
*/
package sc;
import java.awt.*;
import java.awt.event.*;
import java.sql.*;
import javax.swing.*;
public class DelS extends JPanel implements ActionListener{
String save=null;
JTextField 学号1,学号,姓名,性别,年龄,所在系系名;
JButton 删除,查找;
public DelS(){
try {UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());}
catch(Exception e){System.err.println("不能设置外观: "+e);}
学号1=new JTextField(12);
学号=new JTextField(12);
姓名=new JTextField(12);
性别=new JTextField(12);
年龄=new JTextField(12);
所在系系名=new JTextField(12);
删除=new JButton("删除");
查找=new JButton("查找");
Box box1=Box.createHorizontalBox();//横放box
Box box2=Box.createHorizontalBox();
Box box3=Box.createHorizontalBox();
Box box4=Box.createHorizontalBox();
Box box5=Box.createHorizontalBox();
Box box6=Box.createHorizontalBox();
Box box7=Box.createHorizontalBox();
box1.add(new JLabel("学号:",JLabel.CENTER));
box1.add(学号);
box2.add(new JLabel("姓名:",JLabel.CENTER));
box2.add(姓名);
box3.add(new JLabel("性别:",JLabel.CENTER));
box3.add(性别);
box4.add(new JLabel("年龄:",JLabel.CENTER));
box4.add(年龄);
box5.add(new JLabel("所在系系名:",JLabel.CENTER));
box5.add(所在系系名);
box6.add(删除);
box7.add(new JLabel("学号:",JLabel.CENTER));
box7.add(学号1);
box7.add(查找);
Box boxH=Box.createVerticalBox();//竖放box
boxH.add(box1);
boxH.add(box2);
boxH.add(box3);
boxH.add(box4);
boxH.add(box5);
boxH.add(box6);
boxH.add(Box.createVerticalGlue());
删除.addActionListener(this);
查找.addActionListener(this);
JPanel picPanel=new JPanel();
JPanel messPanel=new JPanel();
messPanel.add(box7);
picPanel.add(boxH);
setLayout(new BorderLayout());
JSplitPane splitV=new JSplitPane(JSplitPane.VERTICAL_SPLIT,messPanel,picPanel);//分割
add(splitV,BorderLayout.CENTER);
validate();
}
public void actionPerformed(ActionEvent e){
Object obj=e.getSource();
Statement stmt=null;
ResultSet rs=null,rs1=null;
String sql=null,sql1=null,sqlSC=null;
if(obj==查找){if(学号1.getText().equals(""))JOptionPane.showMessageDialog(this,"请填写查询的学号！" );
else{
sql1="select * from Student where Sno='"+学号1.getText()+"'";
try{
Connection dbConn1=CONN();
stmt=(Statement)dbConn1.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
rs1=stmt.executeQuery(sql1);
if(rs1.next()){学号.setText(rs1.getString("Sno").trim());
姓名.setText(rs1.getString("Sname").trim());
性别.setText(rs1.getString("Ssex").trim());
年龄.setText(rs1.getString("Sage").trim());
所在系系名.setText(rs1.getString("Sdept").trim());
save=学号1.getText().trim();
}
else{JOptionPane.showMessageDialog(this,"没有这个学号的学生" );}
stmt.close();
rs1.close();
}catch(SQLException e1){
System.out.print("SQL Exception occur.Message is:"+e1.getMessage());
}
}
}
else{
if(obj==删除){if(save==null)JOptionPane.showMessageDialog(this,"还没查找需要修改的学生" );
else{sql="delete from Student where Sno='"+save+"'";
sqlSC="delete from SC where Sno='"+save+"'";
try{
Connection dbConn1=CONN();
stmt=(Statement)dbConn1.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
stmt.executeUpdate(sql);
stmt.executeUpdate(sqlSC);
save=null;
JOptionPane.showMessageDialog(this,"删除完成" );
学号.setText("");
姓名.setText("");
性别.setText("");
年龄.setText("");
所在系系名.setText("");
stmt.close();
}catch(SQLException e1){
System.out.print("SQL Exception occur.Message is:"+e1.getMessage());
}
}
}
}
}
public static Connection CONN(){
String driverName = "com.microsoft.sqlserver.jdbc.SQLServerDriver"; //加载JDBC驱动
String dbURL = "jdbc:sqlserver://主机名:1433; DatabaseName=数据库名"; //连接服务器和数据库test
String userName = "sa"; //默认用户名
String userPwd = "密码"; //密码
Connection dbConn=null;
try {
Class.forName(driverName);
dbConn = DriverManager.getConnection(dbURL, userName, userPwd);
System.out.println("Connection Successful!"); //如果连接成功 控制台输出Connection Successful!
} catch (Exception e) {
e.printStackTrace();
}
return dbConn;
}
}
DelSC
/*
DelSC
*/
package sc;
import java.awt.*;
import java.awt.event.*;
import java.sql.*;
import javax.swing.*;
public class DelSC extends JPanel implements ActionListener{
String saveC=null;
String saveS=null;
JTextField 课号1,学号1,学号,课程号,成绩;
JButton 删除,查找;
public DelSC(){
try {UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());}
catch(Exception e){System.err.println("不能设置外观: "+e);}
学号1=new JTextField(12);
课号1=new JTextField(12);
课程号=new JTextField(12);
学号=new JTextField(12);
成绩=new JTextField(12);
删除=new JButton("删除");
查找=new JButton("查找");
Box box1=Box.createHorizontalBox();//横放box
Box box2=Box.createHorizontalBox();
Box box3=Box.createHorizontalBox();
Box box4=Box.createHorizontalBox();
Box box5=Box.createHorizontalBox();
box1.add(new JLabel("课程号:",JLabel.CENTER));
box1.add(课程号);
box2.add(new JLabel("学号:",JLabel.CENTER));
box2.add(学号);
box3.add(new JLabel("成绩:",JLabel.CENTER));
box3.add(成绩);
box4.add(删除);
box5.add(new JLabel("课号:",JLabel.CENTER));
box5.add(课号1);
box5.add(new JLabel("学号:",JLabel.CENTER));
box5.add(学号1);
box5.add(查找);
Box boxH=Box.createVerticalBox();//竖放box
boxH.add(box1);
boxH.add(box2);
boxH.add(box3);
boxH.add(box4);
boxH.add(Box.createVerticalGlue());
删除.addActionListener(this);
查找.addActionListener(this);
JPanel picPanel=new JPanel();
JPanel messPanel=new JPanel();
messPanel.add(box5);
picPanel.add(boxH);
setLayout(new BorderLayout());
JSplitPane splitV=new JSplitPane(JSplitPane.VERTICAL_SPLIT,messPanel,picPanel);//分割
add(splitV,BorderLayout.CENTER);
validate();
}
public void actionPerformed(ActionEvent e){
Object obj=e.getSource();
Statement stmt=null;
ResultSet rs=null,rs1=null;
String sql=null,sql1=null;
if(obj==查找){if(课号1.getText().equals("")||学号1.getText().equals(""))JOptionPane.showMessageDialog(this,"请填写完成查询的信息！" );
else{
sql1="select * from SC where Cno='"+课号1.getText()+"' and Sno='"+学号1.getText()+"'";
try{
Connection dbConn1=CONN();
stmt=(Statement)dbConn1.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
rs1=stmt.executeQuery(sql1);
if(rs1.next()){课程号.setText(rs1.getString("Cno").trim());
学号.setText(rs1.getString("Sno").trim());
成绩.setText(rs1.getString("grade").trim());
saveC=课号1.getText().trim();
saveS=学号1.getText().trim();
}
else{JOptionPane.showMessageDialog(this,"没有这个课号的学生" );}
stmt.close();
rs1.close();
}catch(SQLException e1){
System.out.print("SQL Exception occur.Message is:"+e1.getMessage());
}
}
}
else{
if(obj==删除){if(saveC==null||saveS==null)JOptionPane.showMessageDialog(this,"还没查找需要修改的学生/课程" );
else{sql="delete from SC where Cno='"+saveC+"' and Sno='"+saveS+"'";
try{
Connection dbConn1=CONN();
stmt=(Statement)dbConn1.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
stmt.executeUpdate(sql);
saveC=null;
saveS=null;
JOptionPane.showMessageDialog(this,"删除完成" );
课程号.setText("");
学号.setText("");
成绩.setText("");
stmt.close();
}catch(SQLException e1){
System.out.print("SQL Exception occur.Message is:"+e1.getMessage());
}
}
}
}
}
public static Connection CONN(){
String driverName = "com.microsoft.sqlserver.jdbc.SQLServerDriver"; //加载JDBC驱动
String dbURL = "jdbc:sqlserver://主机名:1433; DatabaseName=数据库名"; //连接服务器和数据库test
String userName = "sa"; //默认用户名
String userPwd = "密码"; //密码
Connection dbConn=null;
try {
Class.forName(driverName);
dbConn = DriverManager.getConnection(dbURL, userName, userPwd);
System.out.println("Connection Successful!"); //如果连接成功 控制台输出Connection Successful!
} catch (Exception e) {
e.printStackTrace();
}
return dbConn;
}
}
SelC
/*
SelC
*/
package sc;
import java.sql.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
public class SelC extends JFrame {
Vector rowData, columnNames;
Statement stmt=null;
String sql=null;
JTable jt = null;
JScrollPane jsp = null;
PreparedStatement ps=null;
ResultSet rs=null;
public SelC(String sql1){
columnNames = new Vector();
// 设置列名
columnNames.add("课程号");
columnNames.add("课程名");
columnNames.add("先修课课程号");
columnNames.add("学分");
rowData=new Vector();
sql=sql1;
try{
Connection dbConn1=CONN();
stmt=(Statement)dbConn1.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
rs=stmt.executeQuery(sql);
while(rs.next()){
Vector hang = new Vector();
hang.add(rs.getString("Cno"));System.out.print(rs.getString("Cno"));
hang.add(rs.getString("Cname"));System.out.print(rs.getString("Cname"));
hang.add(rs.getString("Cpno"));System.out.print(rs.getString("Cpno"));
hang.add(rs.getString("Ccredit"));System.out.print(rs.getString("Ccredit"));
rowData.add(hang);}
jt=new JTable(rowData,columnNames);
jsp=new JScrollPane(jt);
this.add(jsp);
this.setSize(400,300);
this.setVisible(true);
}catch(SQLException e1){
System.out.print("SQL Exception occur.Message is:"+e1.getMessage());
}
}
public static Connection CONN(){
String driverName = "com.microsoft.sqlserver.jdbc.SQLServerDriver"; //加载JDBC驱动
String dbURL = "jdbc:sqlserver://主机名:1433; DatabaseName=数据库名"; //连接服务器和数据库test
String userName = "sa"; //默认用户名
String userPwd = "密码"; //密码
Connection dbConn=null;
try {
Class.forName(driverName);
dbConn = DriverManager.getConnection(dbURL, userName, userPwd);
System.out.println("Connection Successful!"); //如果连接成功 控制台输出Connection Successful!
} catch (Exception e) {
e.printStackTrace();
}
return dbConn;
}
}
SelS
/*
SelS
*/
package sc;
import java.awt.*;
import java.awt.event.*;
import java.sql.*;
import javax.swing.*;
public class SelS extends JPanel implements ActionListener{
JTextField 学号,姓名,性别,年龄,所在系系名;
JButton 查找;
JTextField 课程号,课程名,先修课课程号,学分;
JButton 查找1;
JTextField 课号1,学号1,成绩;
JButton 查找2;
public SelS (){
学号=new JTextField(12);
姓名=new JTextField(12);
性别=new JTextField(12);
年龄=new JTextField(12);
所在系系名=new JTextField(12);
课程号=new JTextField(12);
课程名=new JTextField(12);
先修课课程号=new JTextField(12);
学分=new JTextField(12);
课号1=new JTextField(12);
学号1=new JTextField(12);
成绩=new JTextField(12);
查找=new JButton("查找学生信息");
查找1=new JButton("查找课程信息");
查找2=new JButton("查找选课信息");
Box box1=Box.createHorizontalBox();//横放box
Box box2=Box.createHorizontalBox();
Box box4=Box.createHorizontalBox();
Box box5=Box.createHorizontalBox();
Box box6=Box.createHorizontalBox();
Box box7=Box.createHorizontalBox();
box1.add(new JLabel("学号:",JLabel.CENTER));
box1.add(学号);
box1.add(new JLabel("姓名:",JLabel.CENTER));
box1.add(姓名);
box1.add(new JLabel("性别:",JLabel.CENTER));
box1.add(性别);
box1.add(new JLabel("年龄:",JLabel.CENTER));
box1.add(年龄);
box1.add(new JLabel("所在系系名:",JLabel.CENTER));
box1.add(所在系系名);
box2.add(查找);
box4.add(new JLabel("课程号:",JLabel.CENTER));
box4.add(课程号);
box4.add(new JLabel("课程名:",JLabel.CENTER));
box4.add(课程名);
box4.add(new JLabel("先修课课程号:",JLabel.CENTER));
box4.add(先修课课程号);
box4.add(new JLabel("学分:",JLabel.CENTER));
box4.add(学分);
box6.add(查找1);
box5.add(new JLabel("课程号:",JLabel.CENTER));
box5.add(课号1);
box5.add(new JLabel("学号:",JLabel.CENTER));
box5.add(学号1);
box5.add(new JLabel("成绩:",JLabel.CENTER));
box5.add(成绩);
box7.add(查找2);
Box boxH1=Box.createVerticalBox();//竖放box
boxH1.add(box1);
boxH1.add(box2);
boxH1.add(Box.createVerticalGlue());
Box boxH2=Box.createVerticalBox();//竖放box
boxH2.add(box4);
boxH2.add(box6);
boxH2.add(Box.createVerticalGlue());
Box boxH3=Box.createVerticalBox();//竖放box
boxH3.add(box5);
boxH3.add(box7);
boxH3.add(Box.createVerticalGlue());
查找.addActionListener(this);
查找1.addActionListener(this);
查找2.addActionListener(this);
JPanel messPanel=new JPanel();
JPanel picPanel=new JPanel();
JPanel threePanel=new JPanel();
messPanel.add(boxH1);
picPanel.add(boxH2);
threePanel.add(boxH3);
setLayout(new BorderLayout());
JSplitPane splitV=new JSplitPane(JSplitPane.VERTICAL_SPLIT,messPanel,picPanel);//分割
add(splitV,BorderLayout.CENTER);
JSplitPane splitV1=new JSplitPane(JSplitPane.VERTICAL_SPLIT,splitV,threePanel);//分割
add(splitV1,BorderLayout.CENTER);
validate();
}
public void actionPerformed(ActionEvent c){
Object obj=c.getSource();
Statement stmt=null;
ResultSet rs=null;
int row=0;
int i=0;
String sql=null;
//Student K;
SelC K1;
SelS K2;
if(obj==查找){
if(学号.getText().equals("")&&姓名.getText().equals("")&&性别.getText().equals("")&&年龄.getText().equals("")&&所在系系名.getText().equals("")){
sql="select * from Student ";System.out.print("00");//00
}
else if(学号.getText().equals("")){
if(姓名.getText().equals("")){
if(性别.getText().equals("")){
if(年龄.getText().equals("")) {
sql="select * from Student where Sdept like'%"+所在系系名.getText()+"%'";System.out.print("10");
}
else {
if(所在系系名.getText().equals("")) {
sql="select * from Student where Sage like'%"+年龄.getText()+"%'";System.out.print("10");
}
else {sql="select * from Student where Sage like'%"+年龄.getText()+"%'and Sdept like '%"+所在系系名.getText()+"%'";}
}
}
else {
if(年龄.getText().equals("")) {
if(所在系系名.getText().equals("")) {
sql="select * from Student where Ssex like'%"+性别.getText()+"%'";System.out.print("10");
}
else {sql="select * from Student where Ssex like'%"+性别.getText()+"%'and Sdept like '%"+所在系系名.getText()+"%'";}
}
else {
if(所在系系名.getText().equals("")) {
sql="select * from Student where Sage like'%"+年龄.getText()+"%'and Ssex like '%"+性别.getText()+"%'";System.out.print("10");
}
else {sql="select * from Student where Sage like'%"+年龄.getText()+"%'and Ssex like '%"+性别.getText()+"%'and Sdept like '%"+所在系系名.getText()+"%'";}
}
}
}
else{
if(性别.getText().equals("")){
if(年龄.getText().equals("")) {
if(所在系系名.getText().equals("")) {
sql="select * from Student where Sname like'%"+姓名.getText()+"%'";System.out.print("10");
}
else {sql="select * from Student where Sname like'%"+姓名.getText()+"%'and Sdept like '%"+所在系系名.getText()+"%'";}
}
else {
if(所在系系名.getText().equals("")) {
sql="select * from Student where Sname like'%"+姓名.getText()+"%'and Sage like '%"+年龄.getText()+"%'";System.out.print("10");
}
else {sql="select * from Student where Sname like'%"+姓名.getText()+"%'and Sage like '%"+年龄.getText()+"%'and Sdept like '%"+所在系系名.getText()+"%'";}
}
}
else {
if(年龄.getText().equals("")) {
if(所在系系名.getText().equals("")) {
sql="select * from Student where Ssex like'%"+性别.getText()+"%'and Sname like '%"+姓名.getText()+"%'";System.out.print("10");
}
else {sql="select * from Student where Ssex like'%"+性别.getText()+"%'and Sdept like '%"+所在系系名.getText()+"%'and Sname like '%"+姓名.getText()+"%'";}
}
else {
if(所在系系名.getText().equals("")) {
sql="select * from Student where Sage like'%"+年龄.getText()+"%'and Ssex like '%"+性别.getText()+"%'and Sname like '%"+姓名.getText()+"%'";System.out.print("10");
}
else {sql="select * from Student where Sage like'%"+年龄.getText()+"%'and Ssex like '%"+性别.getText()+"%'and Sdept like '%"+所在系系名.getText()+"%'and Sname like '%"+姓名.getText()+"%'";}
}
}
}
}
else{
if(姓名.getText().equals("")){
if(性别.getText().equals("")){
if(年龄.getText().equals("")) {
if(所在系系名.getText().equals("")) {
sql="select * from Student where Sno like'%"+学号.getText()+"%'";System.out.print("10");
}
else {sql="select * from Student where Sno like'%"+学号.getText()+"%'and Sdept like '%"+所在系系名.getText()+"%'";}
}
else {
if(所在系系名.getText().equals("")) {
sql="select * from Student where Sage like'%"+年龄.getText()+"%'and Sno like '%"+学号.getText()+"%'";System.out.print("10");
}
else {sql="select * from Student where Sage like'%"+年龄.getText()+"%'and Sdept like '%"+所在系系名.getText()+"%'and Sno like '%"+姓名.getText()+"%'";}
}
}
else {
if(年龄.getText().equals("")) {
if(所在系系名.getText().equals("")) {
sql="select * from Student where Ssex like'%"+性别.getText()+"%'and Sno like '%"+学号.getText()+"%'";System.out.print("10");
}
else {sql="select * from Student where Ssex like'%"+性别.getText()+"%'and Sdept like '%"+所在系系名.getText()+"%'and Sno like '%"+学号.getText()+"%'";}
}
else {
if(所在系系名.getText().equals("")) {
sql="select * from Student where Sage like'%"+年龄.getText()+"%'and Ssex like '%"+性别.getText()+"%'and Sno like '%"+学号.getText()+"%'";System.out.print("10");
}
else {sql="select * from Student where Sage like'%"+年龄.getText()+"%'and Ssex like '%"+性别.getText()+"%'and Sdept like '%"+所在系系名.getText()+"%'and Sno like '%"+学号.getText()+"%'";}
}
}
}
else{
if(性别.getText().equals("")){
if(年龄.getText().equals("")) {
if(所在系系名.getText().equals("")) {
sql="select * from Student where Sname like'%"+姓名.getText()+"%'and Sno like '%"+学号.getText()+"%'";System.out.print("10");
}
else {sql="select * from Student where Sname like'%"+姓名.getText()+"%'and Sdept like '%"+所在系系名.getText()+"%'and Sno like '%"+学号.getText()+"%'";}
}
else {
if(所在系系名.getText().equals("")) {
sql="select * from Student where Sname like'%"+姓名.getText()+"%'and Sage like '%"+年龄.getText()+"%'and Sno like '%"+学号.getText()+"%'";System.out.print("10");
}
else {sql="select * from Student where Sname like'%"+姓名.getText()+"%'and Sage like '%"+年龄.getText()+"%'and Sdept like '%"+所在系系名.getText()+"%'and Sno like '%"+学号.getText()+"%'";}
}
}
else {
if(年龄.getText().equals("")) {
if(所在系系名.getText().equals("")) {
sql="select * from Student where Ssex like'%"+性别.getText()+"%'and Sname like '%"+姓名.getText()+"%'and Sno like '%"+学号.getText()+"%'";System.out.print("10");
}
else {sql="select * from Student where Ssex like'%"+性别.getText()+"%'and Sdept like '%"+所在系系名.getText()+"%'and Sname like '%"+姓名.getText()+"%'and Sno like '%"+学号.getText()+"%'";}
}
else {
if(所在系系名.getText().equals("")) {
sql="select * from Student where Sage like'%"+年龄.getText()+"%'and Ssex like '%"+性别.getText()+"%'and Sname like '%"+姓名.getText()+"%'and Sno like '%"+学号.getText()+"%'";System.out.print("10");
}
else {sql="select * from Student where Sage like'%"+年龄.getText()+"%'and Ssex like '%"+性别.getText()+"%'and Sdept like '%"+所在系系名.getText()+"%'and Sname like '%"+姓名.getText()+"%'and Sno like '%"+学号.getText()+"%'";}
}
}
}
}
//K=new Student(sql);
}
else{if(obj==查找1){
if(课程号.getText().equals("")&&课程名.getText().equals("")&&先修课课程号.getText().equals("")&&学分.getText().equals("")){
sql="select * from Course ";System.out.print("00");//00
}
else if(课程号.getText().equals("")){
if(课程名.getText().equals("")){
if(先修课课程号.getText().equals("")){
sql="select * from Course where Ccredit like'%"+学分.getText()+"%'";System.out.print("10");
}
else {
if(学分.getText().equals("")) {sql="select * from Course where Cpno like'%"+先修课课程号.getText()+"%'";System.out.print("10");}
else {sql="select * from Course where Cpno like'%"+先修课课程号.getText()+"%'and Ccredit like '%"+学分.getText()+"%'";}
}
}
else {
if(先修课课程号.getText().equals("")&&学分.getText().equals("")){
sql="select * from Course where Cno like'%"+课程号.getText()+"%'";System.out.print("10");
}
else {
if(先修课课程号.getText().equals("")){
sql="select * from Course where Ccredit like'%"+学分.getText()+"%'and Cno like '%"+课程号.getText()+"%'";System.out.print("10");
}
else {
if(学分.getText().equals("")) {sql="select * from Course where Cpno like'%"+先修课课程号.getText()+"%'and Cno like '%"+课程号.getText()+"%'";System.out.print("10");}
else {sql="select * from Course where Cpno like'%"+先修课课程号.getText()+"%'and Cno like '%"+课程号.getText()+"%'and Ccredit like '%"+学分.getText()+"%'";}
}
}
}
}
else {
if(课程名.getText().equals("")){
if(先修课课程号.getText().equals("")){
if(学分.getText().equals("")) {
sql="select * from Course where Cno like'%"+课程号.getText()+"%'";System.out.print("10");
}
else {sql="select * from Course where Ccredit like'%"+学分.getText()+"%'and Cno like '%"+课程号.getText()+"%'";System.out.print("10");}
}
else {
if(学分.getText().equals("")) {
sql="select * from Course where Cpno like'%"+先修课课程号.getText()+"%'and Cno like '%"+课程号.getText()+"%'";System.out.print("10");
}
else {sql="select * from Course where Ccredit like'%"+学分.getText()+"%'and Cpno like '%"+先修课课程号.getText()+"%'and Cno like '%"+课程号.getText()+"%'";System.out.print("10");}
}
}
else {
if(先修课课程号.getText().equals("")){
if(学分.getText().equals("")) {
sql="select * from Course where Cno like'%"+课程号.getText()+"%'and Cname like '%"+课程名.getText()+"%'";System.out.print("10");
}
else {sql="select * from Course where Ccredit like'%"+学分.getText()+"%'and Cno like '%"+课程号.getText()+"%'and Cname like '%"+课程名.getText()+"%'";System.out.print("10");}
}
else {
if(学分.getText().equals("")) {
sql="select * from Course where Cpno like'%"+先修课课程号.getText()+"%'and Cno like '%"+课程号.getText()+"%'and Cname like '%"+课程名.getText()+"%'";System.out.print("10");
}
else {sql="select * from Course where Ccredit like'%"+学分.getText()+"%'and Cpno like '%"+先修课课程号.getText()+"%'and Cno like '%"+课程号.getText()+"%'and Cname like '%"+课程名.getText()+"%'";System.out.print("10");}
}
}
}
K1=new SelC(sql);}
else{if(obj==查找2){
if(课号1.getText().equals("")&&学号1.getText().equals("")&&成绩.getText().equals("")){
sql="select SC.Cno,Cname,SC.Sno,Sname,grade from SC,Course,Student where Course.Cno=SC.Cno and Student.Sno=SC.Sno";System.out.print("000");//000
}
else{
if(课号1.getText().equals("")){
if(学号1.getText().equals("")){
sql="select SC.Cno,Cname,SC.Sno,Sname,grade from SC,Course,Student where grade like'%"+成绩.getText()+"%' and Course.Cno=SC.Cno and Student.Sno=SC.Sno";System.out.print("001");}
else{if(成绩.getText().equals("")){sql="select SC.Cno,Cname,SC.Sno,Sname,grade from SC,Course,Student where SC.Sno like'%"+学号1.getText()+"%' and Course.Cno=SC.Cno and Student.Sno=SC.Sno";System.out.print("010");}
else{sql="select SC.Cno,Cname,SC.Sno,Sname,grade from SC,Course,Student where SC.Sno like'%"+学号1.getText()+"%'and grade like'%"+成绩.getText()+"%' and Course.Cno=SC.Cno and Student.Sno=SC.Sno";System.out.print("011");}}}
else{if(学号1.getText().equals("")){
if(成绩.getText().equals("")){sql="select SC.Cno,Cname,SC.Sno,Sname,grade from SC,Course,Student where SC.Cno like'%"+课号1.getText()+"%' and Course.Cno=SC.Cno and Student.Sno=SC.Sno";System.out.print("100");}
else{sql="select SC.Cno,Cname,SC.Sno,Sname,grade from SC,Course,Student where SC.Cno like'%"+课号1.getText()+"%' and grade like'%"+成绩.getText()+"%' and Course.Cno=SC.Cno and Student.Sno=SC.Sno";System.out.print("101");}}
else{if(成绩.getText().equals("")){sql="select SC.Cno,Cname,SC.Sno,Sname,grade from SC,Course,Student where SC.Cno like'%"+课号1.getText()+"%' and SC.Sno like'%"+学号1.getText()+"%' and Course.Cno=SC.Cno and Student.Sno=SC.Sno";System.out.print("110");}
else{sql="select SC.Cno,Cname,SC.Sno,Sname,grade from SC,Course,Student where SC.Cno like'%"+课号1.getText()+"%' and SC.Sno like'%"+学号1.getText()+"%' and grade like'%"+成绩.getText()+"%' and Course.Cno=SC.Cno and Student.Sno=SC.Sno";System.out.print("111");}}}
}
K2=new SelS();
}
}
}
}
}
SelSC
/*
SelSC
*/
package sc;
import java.sql.*;
import javax.swing.*;
//import connection.java;
import java.util.*;
public class SelSC extends JFrame {
Vector rowData, columnNames;
Statement stmt=null;
String sql=null;
JTable jt = null;
JScrollPane jsp = null;
PreparedStatement ps=null;
ResultSet rs=null;
public SelSC(String sql1){
columnNames = new Vector();
// 设置列名
columnNames.add("课程号");
columnNames.add("学号");
columnNames.add("成绩");
rowData=new Vector();
sql=sql1;
try{
Connection dbConn1=CONN();
stmt=(Statement)dbConn1.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
rs=stmt.executeQuery(sql);
while(rs.next()){
Vector hang = new Vector();
hang.add(rs.getString("Sno"));System.out.print(rs.getString("Sno"));
hang.add(rs.getString("Cno"));System.out.print(rs.getString("Cno"));
hang.add(rs.getString("grade"));System.out.println(rs.getString("grade"));
rowData.add(hang);}
jt=new JTable(rowData,columnNames);
jsp=new JScrollPane(jt);
this.add(jsp);
this.setSize(400,300);
this.setVisible(true);
}catch(SQLException e1){
System.out.print("SQL Exception occur.Message is:"+e1.getMessage());
}
}
public static Connection CONN(){
String driverName = "com.microsoft.sqlserver.jdbc.SQLServerDriver"; //加载JDBC驱动
String dbURL = "jdbc:sqlserver://主机名:1433; DatabaseName=数据库名"; //连接服务器和数据库test
String userName = "sa"; //默认用户名
String userPwd = "密码"; //密码
Connection dbConn=null;
try {
Class.forName(driverName);
dbConn = DriverManager.getConnection(dbURL, userName, userPwd);
System.out.println("Connection Successful!"); //如果连接成功 控制台输出Connection Successful!
} catch (Exception e) {
e.printStackTrace();
}
return dbConn;
}
}
UpdateC
/*
UpdateC
*/
package sc;
import java.awt.*;
import java.awt.event.*;
import java.sql.*;
import javax.swing.*;
public class UpdateC extends JPanel implements ActionListener{
String save=null;
JTextField 课号1,课程号,课程名,先修课课程号,学分;
JButton 修改,查找;
public UpdateC(){
try {UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());}
catch(Exception e){System.err.println("不能设置外观: "+e);}
课号1=new JTextField(12);
课程号=new JTextField(12);
课程名=new JTextField(12);
先修课课程号=new JTextField(12);
学分=new JTextField(12);
修改=new JButton("修改");
查找=new JButton("查找");
Box box1=Box.createHorizontalBox();//横放box
Box box2=Box.createHorizontalBox();
Box box3=Box.createHorizontalBox();
Box box4=Box.createHorizontalBox();
Box box5=Box.createHorizontalBox();
Box box6=Box.createHorizontalBox();
Box box7=Box.createHorizontalBox();
box1.add(new JLabel("课程号:",JLabel.CENTER));
box1.add(课程号);
box2.add(new JLabel("课程名:",JLabel.CENTER));
box2.add(课程名);
box3.add(new JLabel("先修课课程号:",JLabel.CENTER));
box3.add(先修课课程号);
box4.add(new JLabel("学分:",JLabel.CENTER));
box4.add(学分);
box6.add(修改);
box7.add(new JLabel("课号:",JLabel.CENTER));
box7.add(课号1);
box7.add(查找);
Box boxH=Box.createVerticalBox();//竖放box
boxH.add(box1);
boxH.add(box2);
boxH.add(box3);
boxH.add(box4);
boxH.add(box5);
boxH.add(box6);
修改.addActionListener(this);
查找.addActionListener(this);
boxH.add(Box.createVerticalGlue());
JPanel picPanel=new JPanel();
JPanel messPanel=new JPanel();
messPanel.add(box7);
picPanel.add(boxH);
setLayout(new BorderLayout());
JSplitPane splitV=new JSplitPane(JSplitPane.VERTICAL_SPLIT,messPanel,picPanel);//分割
add(splitV,BorderLayout.CENTER);
validate();
}
public void actionPerformed(ActionEvent e){
Object obj=e.getSource();
Statement stmt=null;
ResultSet rs=null,rs1=null;
String sql=null,sql1=null,sqlSC=null;
if(obj==查找){if(课号1.getText().equals(""))JOptionPane.showMessageDialog(this,"请填写查询的课号！" );
else{
sql1="select * from Course where Cno='"+课号1.getText()+"'";
try{
Connection dbConn1=CONN();
stmt=(Statement)dbConn1.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
rs1=stmt.executeQuery(sql1);
if(rs1.next()){课程号.setText(rs1.getString("Cno").trim());
课程名.setText(rs1.getString("Cname").trim());
先修课课程号.setText(rs1.getString("Cpno").trim());
学分.setText(rs1.getString("Ccredit").trim());
save=课号1.getText();
}
else{JOptionPane.showMessageDialog(this,"没有这个课号的课程" );}
stmt.close();
rs1.close();
}catch(SQLException e1){
System.out.print("SQL Exception occur.Message is:"+e1.getMessage());
}
}
}
else{
if(obj==修改){if(save==null){JOptionPane.showMessageDialog(this,"还没查找需要修改的课程" );}
else{
if(课程号.getText().equals("")||课程名.getText().equals("")||先修课课程号.getText().equals("")||学分.getText().equals("")){
JOptionPane.showMessageDialog(this,"课程信息填满才能修改！" );
}
else{sql="update Course set Cno='"+课程号.getText()+"',Cname='"+课程名.getText()+"',Cpno='"+先修课课程号.getText()+"',Ccredit='"+学分.getText()+"' where Cno='"+save+"'";
if(save.trim().equals(课程号.getText().trim())){
try{
Connection dbConn1=CONN();
stmt=(Statement)dbConn1.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
stmt.executeUpdate(sql);
save=null;
JOptionPane.showMessageDialog(this,"修改完成" );
课程号.setText("");
课程名.setText("");
stmt.close();
}catch(SQLException e1){
System.out.print("SQL Exception occur.Message is:"+e1.getMessage());
}
}
else{sql1="select * from Course where Cno='"+课程号.getText()+"'";
try{
Connection dbConn1=CONN();
stmt=(Statement)dbConn1.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
rs1=stmt.executeQuery(sql1);
if(rs1.next()){ JOptionPane.showMessageDialog(this,"已存在此课号课程" );
}
else{sqlSC="update SC set Cno='"+课程号.getText()+"' where Cno='"+save+"'";
stmt.executeUpdate(sql);
stmt.executeUpdate(sqlSC);
save=null;
JOptionPane.showMessageDialog(null,"修改完成" );
课程号.setText("");
课程名.setText("");
先修课课程号.setText("");
学分.setText("");}
stmt.close();
rs1.close();
}catch(SQLException e1){
System.out.print("SQL Exception occur.Message is:"+e1.getMessage());
}
}
}}}}
}
public static Connection CONN(){
String driverName = "com.microsoft.sqlserver.jdbc.SQLServerDriver"; //加载JDBC驱动
String dbURL = "jdbc:sqlserver://主机名:1433; DatabaseName=数据库名"; //连接服务器和数据库test
String userName = "sa"; //默认用户名
String userPwd = "密码"; //密码
Connection dbConn=null;
try {
Class.forName(driverName);
dbConn = DriverManager.getConnection(dbURL, userName, userPwd);
System.out.println("Connection Successful!"); //如果连接成功 控制台输出Connection Successful!
} catch (Exception e) {
e.printStackTrace();
}
return dbConn;
}
}
UpdateS
/*
UpdateS
*/
package sc;
import java.awt.*;
import java.awt.event.*;
import java.sql.*;
import javax.swing.*;
public class UpdateS extends JPanel implements ActionListener{
String save=null;
JTextField 学号1,学号,姓名,性别,年龄,所在系系名;
JButton 修改,查找;
public UpdateS(){
try {UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());}
catch(Exception e){System.err.println("不能设置外观: "+e);}
学号1=new JTextField(12);
学号=new JTextField(12);
姓名=new JTextField(12);
性别=new JTextField(12);
年龄=new JTextField(12);
所在系系名=new JTextField(12);
修改=new JButton("修改");
查找=new JButton("查找");
Box box1=Box.createHorizontalBox();//横放box
Box box2=Box.createHorizontalBox();
Box box3=Box.createHorizontalBox();
Box box4=Box.createHorizontalBox();
Box box5=Box.createHorizontalBox();
Box box6=Box.createHorizontalBox();
Box box7=Box.createHorizontalBox();
box1.add(new JLabel("学号:",JLabel.CENTER));
box1.add(学号);
box2.add(new JLabel("姓名:",JLabel.CENTER));
box2.add(姓名);
box3.add(new JLabel("性别:",JLabel.CENTER));
box3.add(性别);
box4.add(new JLabel("年龄:",JLabel.CENTER));
box4.add(年龄);
box5.add(new JLabel("所在系系名:",JLabel.CENTER));
box5.add(所在系系名);
box6.add(修改);
box7.add(new JLabel("学号:",JLabel.CENTER));
box7.add(学号1);
box7.add(查找);
修改.addActionListener(this);
查找.addActionListener(this);
Box boxH=Box.createVerticalBox();//竖放box
boxH.add(box1);
boxH.add(box2);
boxH.add(box3);
boxH.add(box4);
boxH.add(box5);
boxH.add(box6);
boxH.add(Box.createVerticalGlue());
JPanel picPanel=new JPanel();
JPanel messPanel=new JPanel();
messPanel.add(box7);
picPanel.add(boxH);
setLayout(new BorderLayout());
JSplitPane splitV=new JSplitPane(JSplitPane.VERTICAL_SPLIT,messPanel,picPanel);//分割
add(splitV,BorderLayout.CENTER);
validate();
}
public void actionPerformed(ActionEvent e){
Object obj=e.getSource();
Statement stmt=null;
ResultSet rs=null,rs1=null;
String sql=null,sql1=null,sqlSC;
if(obj==查找){if(学号1.getText().equals(""))JOptionPane.showMessageDialog(this,"请填写查询的学号！" );
else{
sql1="select * from Student where Sno='"+学号1.getText()+"'";
try{
Connection dbConn1=CONN();
stmt=(Statement)dbConn1.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
rs1=stmt.executeQuery(sql1);
if(rs1.next()){学号.setText(rs1.getString("Sno").trim());
姓名.setText(rs1.getString("Sname").trim());
性别.setText(rs1.getString("Ssex").trim());
年龄.setText(rs1.getString("Sage").trim());
所在系系名.setText(rs1.getString("Sdept").trim());
save=学号1.getText();
}
else{JOptionPane.showMessageDialog(this,"没有这个学号的学生" );}
stmt.close();
rs1.close();
}catch(SQLException e1){
System.out.print("SQL Exception occur.Message is:"+e1.getMessage());
}
}
}
else{
if(obj==修改){if(save==null){JOptionPane.showMessageDialog(this,"还没查找需要修改的学生" );}
else{
if(学号.getText().equals("")||姓名.getText().equals("")||性别.getText().equals("")||年龄.getText().equals("")||所在系系名.getText().equals("")){
JOptionPane.showMessageDialog(this,"学生信息填满才能修改！" );
}
else{sql="update Student set Sno='"+学号.getText()+"',Sname='"+姓名.getText()+"',Ssex='"+性别.getText()+"',Sage='"+年龄.getText()+"',Sdept='"+所在系系名.getText()+"'where Sno='"+save+"'";
if(save.trim().equals(学号.getText().trim())){
try{
Connection dbConn1=CONN();
stmt=(Statement)dbConn1.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
stmt.executeUpdate(sql);
save=null;
JOptionPane.showMessageDialog(this,"修改完成" );
学号.setText("");
姓名.setText("");
性别.setText("");
年龄.setText("");
所在系系名.setText("");
stmt.close();
}catch(SQLException e1){
System.out.print("SQL Exception occur.Message is:"+e1.getMessage());
}
}
else{sql1="select * from Student where Sno='"+学号.getText()+"'";
try{
Connection dbConn1=CONN();
stmt=(Statement)dbConn1.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
rs1=stmt.executeQuery(sql1);
if(rs1.next()){ JOptionPane.showMessageDialog(this,"已存在此学号学生" );
}
else{
sqlSC="update SC set Sno='"+学号.getText()+"' where Sno='"+save+"'";
stmt.executeUpdate(sql);
stmt.executeUpdate(sqlSC);
save=null;
JOptionPane.showMessageDialog(null,"修改完成" );
学号.setText("");
姓名.setText("");
性别.setText("");
年龄.setText("");
所在系系名.setText("");}
stmt.close();
rs1.close();
}catch(SQLException e1){
System.out.print("SQL Exception occur.Message is:"+e1.getMessage());
}
}
}}}}
}
public static Connection CONN(){
String driverName = "com.microsoft.sqlserver.jdbc.SQLServerDriver"; //加载JDBC驱动
String dbURL = "jdbc:sqlserver://主机名:1433; DatabaseName=数据库名"; //连接服务器和数据库test
String userName = "sa"; //默认用户名
String userPwd = "密码"; //密码
Connection dbConn=null;
try {
Class.forName(driverName);
dbConn = DriverManager.getConnection(dbURL, userName, userPwd);
System.out.println("Connection Successful!"); //如果连接成功 控制台输出Connection Successful!
} catch (Exception e) {
e.printStackTrace();
}
return dbConn;
}
}
UpdateSC
/*
UpdateSC
*/
package sc;
import java.awt.*;
import java.awt.event.*;
import java.sql.*;
import javax.swing.*;
public class UpdateSC extends JPanel implements ActionListener{
String saveC=null;
String saveS=null;
JTextField 课号1,学号1,学号,课程号,成绩;
JButton 修改,查找;
public UpdateSC(){
try {UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());}
catch(Exception e){System.err.println("不能设置外观: "+e);}
学号1=new JTextField(12);
课号1=new JTextField(12);
课程号=new JTextField(12);
学号=new JTextField(12);
成绩=new JTextField(12);
修改=new JButton("修改");
查找=new JButton("查找");
Box box1=Box.createHorizontalBox();//横放box
Box box2=Box.createHorizontalBox();
Box box3=Box.createHorizontalBox();
Box box4=Box.createHorizontalBox();
Box box5=Box.createHorizontalBox();
box1.add(new JLabel("课程号:",JLabel.CENTER));
box1.add(课程号);
box2.add(new JLabel("学号:",JLabel.CENTER));
box2.add(学号);
box3.add(new JLabel("成绩:",JLabel.CENTER));
box3.add(成绩);
box4.add(修改);
box5.add(new JLabel("课号:",JLabel.CENTER));
box5.add(课号1);
box5.add(new JLabel("学号:",JLabel.CENTER));
box5.add(学号1);
box5.add(查找);
Box boxH=Box.createVerticalBox();//竖放box
boxH.add(box1);
boxH.add(box2);
boxH.add(box3);
boxH.add(box4);
boxH.add(Box.createVerticalGlue());
修改.addActionListener(this);
查找.addActionListener(this);
JPanel picPanel=new JPanel();
JPanel messPanel=new JPanel();
messPanel.add(box5);
picPanel.add(boxH);
setLayout(new BorderLayout());
JSplitPane splitV=new JSplitPane(JSplitPane.VERTICAL_SPLIT,messPanel,picPanel);//分割
add(splitV,BorderLayout.CENTER);
validate();
}
public void actionPerformed(ActionEvent e){
Object obj=e.getSource();
Statement stmt=null;
ResultSet rs=null,rs1=null,rsC=null,rsS=null;
String sql,sql1,sqlS,sqlC;
if(obj==查找){if(课号1.getText().equals("")||学号1.getText().equals(""))JOptionPane.showMessageDialog(this,"请填写完成查询的信息！" );
else{
sql1="select * from SC where Cno='"+课号1.getText()+"' and Sno='"+学号1.getText()+"'";
try{
Connection dbConn1=CONN();
stmt=(Statement)dbConn1.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
rs1=stmt.executeQuery(sql1);
if(rs1.next()){课程号.setText(rs1.getString("Cno").trim());
学号.setText(rs1.getString("Sno").trim());
成绩.setText(rs1.getString("grade").trim());
saveC=课号1.getText().trim();
saveS=学号1.getText().trim();
}
else{JOptionPane.showMessageDialog(this,"没有这个课号的学生" );}
stmt.close();
rs1.close();
}catch(SQLException e1){
System.out.print("SQL Exception occur.Message is:"+e1.getMessage());
}
}
}
else{
if(obj==修改){if(saveC==null||saveS==null)JOptionPane.showMessageDialog(this,"还没查找需要修改的学生/课程" );
else{
if(课程号.getText().equals("")||学号.getText().equals("")){
JOptionPane.showMessageDialog(this,"课程信息填满才能修改！" );
}
else{
sqlC="select * from Course where Cno='"+课程号.getText()+"'";
sqlS="select * from Student where Sno='"+学号.getText()+"'";
sql1="select * from SC where Cno='"+课程号.getText()+"' and Sno='"+学号.getText()+"'";
sql="update SC set Cno='"+课程号.getText()+"',Sno='"+学号.getText()+"',grade='"+成绩.getText()+"' where Cno='"+saveC+"' and Sno='"+saveS+"'";
try{
Connection dbConn1=CONN();
stmt=(Statement)dbConn1.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
rsC=stmt.executeQuery(sqlC);
if(rsC.next()){
rsS=stmt.executeQuery(sqlS);
if(rsS.next()){
if(课程号.getText().trim().equals(saveC)&& 学号.getText().trim().equals(saveS)){
stmt.executeUpdate(sql);
JOptionPane.showMessageDialog(this,"添加成功");
saveC=null;
saveS=null;
}
else{rs1=stmt.executeQuery(sql1);
if(rs1.next()){JOptionPane.showMessageDialog(this,"学生与课程号以存在，无法修改");}
else{
stmt.executeUpdate(sql);
JOptionPane.showMessageDialog(this,"添加成功");
saveC=null;
saveS=null;
}
rs1.close();
}
}
else{JOptionPane.showMessageDialog(this,"该学生不存在，无法修改");}
rsS.close();
}
else{JOptionPane.showMessageDialog(this,"该课程不存在，无法修改");}
rsC.close();
stmt.close();
}
catch(SQLException e1){
System.out.print("SQL Exception occur.Message is:"+e1.getMessage());
}
}
}
}
}
}
public static Connection CONN(){
String driverName = "com.microsoft.sqlserver.jdbc.SQLServerDriver"; //加载JDBC驱动
String dbURL = "jdbc:sqlserver://主机名:1433; DatabaseName=数据库名"; //连接服务器和数据库test
String userName = "sa"; //默认用户名
String userPwd = "密码"; //密码
Connection dbConn=null;
try {
Class.forName(driverName);
dbConn = DriverManager.getConnection(dbURL, userName, userPwd);
System.out.println("Connection Successful!"); //如果连接成功 控制台输出Connection Successful!
} catch (Exception e) {
e.printStackTrace();
}
return dbConn;
}
}
Menu
package sc;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Menu extends JFrame implements ActionListener{
AddS 增加学生界面;
UpdateS 修改学生界面;
DelS 删除学生界面;
AddC 增加课程界面;
DelC 删除课程界面;
UpdateC 修改课程界面;
AddSC 增加选课界面;
DelSC 删除选课界面;
UpdateSC 修改选课界面;
SelS 学生查询界面;
JPanel pCenter;
CardLayout card=null;
JLabel label=null;
JMenuBar mb=new JMenuBar();//菜单栏
JMenu m1=new JMenu("学生管理");
JMenuItem add1=new JMenuItem("add ");
JMenuItem updata1=new JMenuItem("update ");
JMenuItem delete1=new JMenuItem("delete ");
JMenu m2=new JMenu("课程管理");
JMenuItem add2=new JMenuItem("add ");
JMenuItem updata2=new JMenuItem("update ");
JMenuItem delete2=new JMenuItem("delete ");
JMenu m3=new JMenu("选课管理");
JMenuItem add3=new JMenuItem("add ");
JMenuItem updata3=new JMenuItem("update ");
JMenuItem delete3=new JMenuItem("delete ");
JMenu m4=new JMenu("查询管理");
JMenuItem 学生查询=new JMenuItem("查询信息 ");
JMenuItem m5=new JMenuItem("系统退出");
Font t=new Font ("sanerif",Font.PLAIN,12);
public Menu (){
this.setTitle("学生成绩管理系统");
try {UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());}
catch(Exception e){System.err.println("不能设置外观: "+e);}
//组合菜单
addMenu1();
addMenu2();
addMenu3();
addMenu4();
addJMenuBar();
setJMenuBar(mb);
label=new JLabel("BJTU成绩管理系统",JLabel.CENTER);
label.setFont(new Font("宋体",Font.BOLD,36));
label.setHorizontalTextPosition(SwingConstants.CENTER);
label.setForeground(Color.blue);
//点击事件
add1.addActionListener(this);
updata1.addActionListener(this);
delete1.addActionListener(this);
m5.addActionListener(this);
add2.addActionListener(this);
delete2.addActionListener(this);
updata2.addActionListener(this);
add3.addActionListener(this);
delete3.addActionListener(this);
updata3.addActionListener(this);
学生查询.addActionListener(this);
card=new CardLayout();
pCenter=new JPanel();
pCenter.setLayout(card);
增加学生界面=new AddS();
修改学生界面=new UpdateS();
删除学生界面=new DelS();
增加课程界面=new AddC();
删除课程界面=new DelC();
修改课程界面=new UpdateC();
增加选课界面=new AddSC();
删除选课界面=new DelSC();
修改选课界面=new UpdateSC();
学生查询界面=new SelS();
pCenter.add("欢迎界面",label);
pCenter.add("增加学生界面",增加学生界面);
pCenter.add("修改学生界面",修改学生界面);
pCenter.add("删除学生界面",删除学生界面);
pCenter.add("增加课程界面",增加课程界面);
pCenter.add("删除课程界面",删除课程界面);
pCenter.add("修改课程界面",修改课程界面);
pCenter.add("增加选课界面",增加选课界面);
pCenter.add("删除选课界面",删除选课界面);
pCenter.add("修改选课界面",修改选课界面);
pCenter.add("学生查询界面", 学生查询界面);
add(pCenter,BorderLayout.CENTER);
validate();
setVisible(true);
setBounds(400,150,1200,790);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
addWindowListener(new WindowAdapter(){//关闭程序时的操作
public void windowClosing(WindowEvent e){System.exit(0);}
});
validate();
}
private void addJMenuBar() {
mb.add(m1);mb.add(m2);mb.add(m3);mb.add(m4);mb.add(m5);
}
private void addMenu4() {
m4.add(学生查询);
m4.setFont(t);
}
private void addMenu3() {
m3.add(add3);
m3.add(updata3);
m3.add(delete3);
m3.setFont(t);
}
private void addMenu2() {//将菜单加入到菜单栏中
m2.add(add2);
m2.add(updata2);
m2.add(delete2);
m2.setFont(t);
}
private void addMenu1() {
m1.add(add1);
m1.add(updata1);
m1.add(delete1);
m1.setFont(t);//字体
}
public void actionPerformed(ActionEvent e){
Object obj=e.getSource();
if(obj==m5){System.exit(0);}
else{if(obj==add1){
card.show(pCenter,"增加学生界面");
}
else{if(obj==updata1){
card.show(pCenter,"修改学生界面");
}
else{if(obj==delete1){
card.show(pCenter, "删除学生界面");
}
else{if(obj==add2){
card.show(pCenter, "增加课程界面");
}
else{if(obj==delete2){
card.show(pCenter, "删除课程界面");
}
else{if(obj==updata2){
card.show(pCenter, "修改课程界面");
}
else{if(obj==add3){
card.show(pCenter, "增加选课界面");
}
else{if(obj==delete3){
card.show(pCenter, "删除选课界面");
}
else{if(obj==updata3){
card.show(pCenter, "修改选课界面");
}
else{if(obj==学生查询){
card.show(pCenter, "学生查询界面");
}}
}}}}}}}}}}
public static void main(String[] args) {
new Menu();
}
}
- 需求分析
-
- E-R图
-
- 逻辑关系
- 物理设计和实施
-
- 创建包、Add、Del、Update、Sel
- idea链接数据库
-
- 简单SQL语句
-
- 答辩
idea链接数据库
File+settings+editor+plugins+database navigator+apply+ok
出现感叹号：
进connection+properties+serverTimezone+Asia/Shanghai+test connection
简单SQL语句
按老师要求还是进行一点语句补充吧(如果觉得费钱就把重复的代码保留一个表的，其他的做文字说明就可以了）
建表：
CREATE TABLE student(
sno CHAR(10),
sname VARCHAR(20),
ssex CHAR(2),
sage INT,
sdept CHAR(15)
);
增：
insert into 表名(属性1，属性2）value ('内容1','内容2')
删：
delete from 表名 where 学号='****'
改：
update 表名 set 成绩=NULL
查：
select student.sno,sname,ssex,sage,sdept,cno
from 学生成绩管理.student,学生成绩管理.sc
where 学生成绩管理.student.sno=学生成绩管理.sc.sno
对成绩的查询：
select student.sname ,grade
from 学生成绩管理.student,学生成绩管理.sc
where 学生成绩管理.student.sno=学生成绩管理.sc.sno
//不优秀的学生学号、课程号、成绩
select sno,cno,grade
from 学生成绩管理.sc
where grade80;
//不优秀课程的学生学号
select distinct sno
from 学生成绩管理.sc
where grade80;
//所有课程信息及选修该课程的学生学号及成绩
select cname,sno,grade
from 学生成绩管理.sc,学生成绩管理.course
where 学生成绩管理.course.cno =学生成绩管理.sc.cno
/*选修5号课程成绩80分以上学生学号姓名及成绩
select student.sno,sname,grade
from 学生成绩管理.sc
where 学生成绩管理.student.sno=学生成绩管理.sc.sno
and sc.cno='5'
and sc.grade>80
*/
//每个学生及选修课程名及成绩
select student.sno,sname,cname,sc.grade
from 学生成绩管理.student,学生成绩管理.sc,学生成绩管理.course
where student.sno=sc.sno
and sc.cno=course.cno
对成绩的统计：
1、使用MAX ()函数统计某个字段最大数据；
2、使用MIN ()函数统计某个字段最小数据；
3、使用COUNT ()函数统计查询结果的行数；
4、使用SUM ()函数统计数据之和；
5、使用AVG ()函数统计平均数。 MySQL MAX () 函数
答辩
好了好了就到这里，答辩讲解需求分析和E-R图为主，明天答辩祝我自己好运，过过过
