Java数据库进行密码验证

Question

package study;import java.sql.;import java.util.;public class Studys { static Connection con = null; //用于执行语句 static Statement stmt = null; //用于接受结果 static ResultSet rs = null; static String url = "jdbc:sqlserver://localhost:1433;Datebasename=rwkdb;"; static Scanner input = new Scanner(System.in); public static void Menu() { System.out.println("欢迎使用学生信息管理系统 "); System.out.println(" （1）查询 （2）修改 "); System.out.println(" （3）增加 （4）删除 "); System.out.println(" （5）退出 "); System.out.println(""); }public static void Search() throws SQLException { try { //连接数据库 con = DriverManager.getConnection(url,"sa","root"); //按名字查（SQL) String sql_name = "select id,sname,ssex,sage from stu where sname=?"; //按课程名查(SQL)// String sql_c = "select Sname,Score from Studys..S,Studys..SC,Studys..C where C.Cname = ? and C.Cno = SC.Cno and SC.Sno = S.Sno"; PreparedStatement name = con.prepareStatement(sql_name);//按名字查询// PreparedStatement c = con.prepareStatement(sql_c);//按课程名查 System.out.println("请选择查询方式："); System.out.println("(1)姓名查询 "); int select = 0; select = input.nextInt(); switch(select) { case 1: System.out.println("请输入要查询的名字："); String s = input.next(); name.setString(1, s); rs = name.executeQuery(); System.out.println(""); System.out.println("学号"+"\t\t"+"姓名"+"\t\t"+"性别"+"\t\t"+"年龄"); while(rs.next()) { int id = rs.getInt("id"); String sname = rs.getString("sname"); String ssex = rs.getString("ssex"); int sage = rs.getInt("sage"); System.out.println(id+"\t\t"+sname+"\t\t"+ssex+"\t\t"+sage); } System.out.println(""); break;// case 2:// System.out.println("请输入要查询的课程名：");// String s1 = input.next();// c.setString(1, s1);// rs = c.executeQuery();// System.out.println("");// System.out.println("学生名称"+"\t\t"+"成绩");// while(rs.next()) {// String Sname = rs.getString("Sname");// int Score = rs.getInt("Score");// System.out.println(Sname+"\t\t"+Score);// }// System.out.println("**************");// break; default: System.out.println("无此选项！"); break; } /while(rs.next()) { int id = rs.getInt("Sno"); String Sname = rs.getString("Sname"); String Ssex = rs.getString("Ssex"); int Sage = rs.getInt("Sage"); String Sdept = rs.getString("Sdept"); System.out.println(id+"\t"+Sname+"\t"+Ssex+"\t"+Sage+"\t"+Sdept); }/ }catch(SQLException e) { e.printStackTrace(); System.out.println("数据连接错误！！！"); }finally{ if(rs!=null) { rs.close(); } if(stmt!=null) { stmt.close(); } if(con!=null) { con.close(); } }}//修改public static void Change() throws SQLException { try { //连接数据库 con = DriverManager.getConnection(url,"sa","root"); //修改（SQL) String sql_change = "update stu set Sname = ?,Ssex = ?,Sage = ? where id = ?"; String sql = "select * from stu where id = ?"; PreparedStatement name = con.prepareStatement(sql_change); PreparedStatement information = con.prepareStatement(sql); String sname;//名字 String ssex; int sage; int id; System.out.println("请输入要修改的学生的学号："); id = input.nextInt(); information.setInt(1, id); rs = information.executeQuery(); System.out.println("该学生的信息如下："); System.out.println("******************************"); System.out.println("学号\t姓名\t性别\t年龄"); while(rs.next()) { id = rs.getInt("id"); sname = rs.getString("Sname"); ssex = rs.getString("Ssex"); sage = rs.getInt("Sage"); System.out.println(id+"\t"+sname+"\t"+ssex+"\t"+sage); } System.out.println(""); System.out.println("请输入修改后的姓名："); sname = input.next(); name.setString(1, sname); System.out.println("请输入修改后的性别："); ssex = input.next(); name.setString(2, ssex); System.out.println("请输入修改后的年龄："); sage = input.nextInt(); name.setInt(3, sage); name.setInt(4, id); name.executeUpdate(); System.out.println("修改成功"); System.out.println("修改后的学生信息如下："); information.setInt(1, id); rs = information.executeQuery(); System.out.println(""); System.out.println("学号\t姓名\t性别\t年龄"); while(rs.next()) { id = rs.getInt("id"); sname = rs.getString("Sname"); ssex = rs.getString("Ssex"); sage = rs.getInt("Sage"); System.out.println(id+"\t"+sname+"\t"+ssex+"\t"+sage); } System.out.println("************************************"); }catch(SQLException e) {

Answer 1

问题是什么？报错吗，还是实现不了你的需求。