xuanobject.java

本系统是基于CORBA实现的选课系统,具有一般选课系统的基本功能(查看学生基本信息,选课退课,查看成绩等),本系统主要是推荐给对刚进行CORBA学习的初学者来说有很大的重要性

            // 执行查询，并返回一个结果集
			sql.executeUpdate(update1);	
			
			String query = "select * from course_DT where courseid = '"+cid+"'";
			ResultSet result = sql.executeQuery(query);
			
			String xuefen1 = new String();
			while(result.next())
			{
				xuefen1 = result.getString("xuefen");
			}
			String update2 = "insert into score_DT values('"+sid+"','"+cid+"','"+xuefen1+"',0.0)";
			sql.executeUpdate(update2);
			// 关闭声明和连接
			sql.close();
			con.close();

		} catch (java.lang.ClassNotFoundException e) {
			// 加载jdbc错误，所要用的驱动没找到
			e.printStackTrace();
			System.out.println("dfsdf"); 
			// 其他错误
		} catch (SQLException ex) {
			System.err.println("SQLException: " + ex.getMessage());
			// 显示数据库连接错误或者查询错误
		}
	}
	
	public void deletecourse(String cid,String sid)
	{
		try {
			// 取得数据库的连接
			Connection con = this.getConnection();
			// 创建一个声明，用来执行sql语句
			Statement sql = con.createStatement();
			// 执行查询数据库的sql语句
			String update1="delete from choose_DT where courseid='"+cid+"' and stuid='"+sid+"'";
            // 执行查询，并返回一个结果集
			sql.executeUpdate(update1);	
			String update2 = "delete from score_DT where courseid='"+cid+"' and stuid='"+sid+"'";
			sql.executeUpdate(update2);
			// 关闭声明和连接
			sql.close();
			con.close();

		} catch (java.lang.ClassNotFoundException e) {
			// 加载jdbc错误，所要用的驱动没找到
			e.printStackTrace();
			System.out.println("dfsdf"); 
			// 其他错误
		} catch (SQLException ex) {
			System.err.println("SQLException: " + ex.getMessage());
			// 显示数据库连接错误或者查询错误
		}
	}
	
	public void getcourselist(String sid,String year1)
	{
		try {
			// 取得数据库的连接
			Connection con = this.getConnection();
			// 创建一个声明，用来执行sql语句
			Statement sql = con.createStatement();
			// 执行查询数据库的sql语句
			//if((term.substring(4,4)).equals("春"))
			//String query="select * from course_DT where courseid like '%"+term.substring(0,3)+"%'";
			String query="select * from course_DT where courseid in"+
			             "(select courseid from choose_DT where stuid='"+sid+"'"+
			             " and courseid like '"+year1+"%')";
            // 执行查询，并返回一个结果集
			ResultSet result = sql.executeQuery(query);
 			
 			int i=0;
 			courseid = "";
 			coursename= "";
 			//xuefen = "";
 			classtime = "";
 			teachername= "";
 			room= "";
 			examtime= "";
 			courseinf= "";
 			
 			StringBuffer a = new StringBuffer();
 			while(result.next())
 			{
 				String courseid1 = result.getString("courseid");
 				String coursename1 = result.getString("coursename");
 				//String xuefen1 = result.getString("xuefen");
 				String classtime1 = result.getString("classtime");
 				String teachername1 = result.getString("teachername");
 				String room1 = result.getString("room");
 				String examtime1 = result.getString("examtime");
 				String courseinf1 = result.getString("courseinf");
 				courseid += courseid1 + ",";
 				coursename += coursename1 +",";
 				//xuefen = xuefen1 + ",";
 				classtime += classtime1 +",";
 				teachername += teachername1 +",";
 				room += room1 +",";
 				examtime += examtime1 +",";
 				courseinf += courseinf1 +",";
 				i++;
 			}
 			row = i;
 			System.out.println("The student has choose "+i+" courses");
			// 关闭声明和连接
			sql.close();
			con.close();

		} catch (java.lang.ClassNotFoundException e) {
			// 加载jdbc错误，所要用的驱动没找到
			e.printStackTrace();
			System.out.println("dfsdf"); 
			// 其他错误
		} catch (SQLException ex) {
			System.err.println("SQLException: " + ex.getMessage());
			// 显示数据库连接错误或者查询错误
		}
	}
	
	private String score;
	public void getscorelist(String sid,String year1)
	{
		try {
			// 取得数据库的连接
			Connection con = this.getConnection();
			// 创建一个声明，用来执行sql语句
			Statement sql = con.createStatement();
			// 执行查询数据库的sql语句
			String query="select course_DT.courseid,coursename,classtime,"+
			             "teachername,score from course_DT,score_DT"+
			             " where stuid='"+sid+"' and score_DT.courseid like '"+year1+"%'"+
			             " and course_DT.courseid = score_DT.courseid";
            // 执行查询，并返回一个结果集
			ResultSet result = sql.executeQuery(query);
 			System.out.println(year1);
 			System.out.println(sid);
 			int i=0;
 			courseid = "";
 			coursename= "";
 			classtime = "";
 			teachername= "";
 			score = "";
 			System.out.println("got score");
 			while(result.next())
 			{
 				String courseid1 = result.getString("courseid");
 				String coursename1 = result.getString("coursename");
 				String classtime1 = result.getString("classtime");
 				String teachername1 = result.getString("teachername");
 				String score1 = result.getString("score");
 				score += score1 + ",";
 				courseid += courseid1 + ",";
 				coursename += coursename1 +",";
 				classtime += classtime1 +",";
 				teachername += teachername1 +",";
 				i++;
 			}
 			row = i;
 			System.out.println("score courses "+i);
			// 关闭声明和连接
			sql.close();
			con.close();

		} catch (java.lang.ClassNotFoundException e) {
			// 加载jdbc错误，所要用的驱动没找到
			e.printStackTrace();
			System.out.println("dfsdf"); 
			// 其他错误
		} catch (SQLException ex) {
			System.err.println("SQLException: " + ex.getMessage());
			// 显示数据库连接错误或者查询错误
		}
	}
	
	public String getscore()
	{
		return score;
	}
	
	public void getchooselist(String sid)
	{
		java.util.GregorianCalendar aDate = new java.util.GregorianCalendar();
		int year = aDate.get(Calendar.YEAR);
		System.out.println("The year is "+year);
		try {
			// 取得数据库的连接
			Connection con = this.getConnection();
			// 创建一个声明，用来执行sql语句
			Statement sql = con.createStatement();
			// 执行查询数据库的sql语句
			String query="select course_DT.courseid,coursename,xuefen,classtime,"+
			             "teachername,room,examtime from course_DT,choose_DT"+
			             " where stuid='"+sid+"' and choose_DT.courseid like '%"+year+"%'"+
			             " and course_DT.courseid = choose_DT.courseid";
            // 执行查询，并返回一个结果集
			ResultSet result = sql.executeQuery(query);
 			
 			int i=0;
 			courseid = "";
 			coursename= "";
 			xuefen = "";
 			classtime = "";
 			teachername= "";
 			room = "";
 			examtime = "";
 			System.out.println("The year is "+year);
 			while(result.next())
 			{
 				String courseid1 = result.getString("courseid");
 				String coursename1 = result.getString("coursename");
 				String xuefen1 = result.getString("xuefen");
 				String classtime1 = result.getString("classtime");
 				String teachername1 = result.getString("teachername");
 				String room1 = result.getString("room");
 				String examtime1 = result.getString("examtime");
 				courseid += courseid1 + ",";
 				coursename += coursename1 +",";
 				xuefen += xuefen1 + ",";
 				classtime += classtime1 +",";
 				teachername += teachername1 +",";
 				room += room1 +",";
 				examtime += examtime1 +",";
 				i++;
 			}
 			row = i;
 			System.out.println("The choose course"+i);
			// 关闭声明和连接
			sql.close();
			con.close();

		} catch (java.lang.ClassNotFoundException e) {
			// 加载jdbc错误，所要用的驱动没找到
			e.printStackTrace();
			System.out.println("dfsdf"); 
			// 其他错误
		} catch (SQLException ex) {
			System.err.println("SQLException: " + ex.getMessage());
			// 显示数据库连接错误或者查询错误
		}
	}
	public int getxuefentotal(String sid)
	{
		int i=0;
		try {
			// 取得数据库的连接
			Connection con = this.getConnection();
			// 创建一个声明，用来执行sql语句
			Statement sql = con.createStatement();
			// 执行查询数据库的sql语句
			//if((term.substring(4,4)).equals("春"))
			//String query="select * from course_DT where courseid like '%"+term.substring(0,3)+"%'";
			String query="select * from score_DT where stuid='"+sid+"'";
            // 执行查询，并返回一个结果集
			ResultSet result = sql.executeQuery(query);			
 			
 			while(result.next())
 			{
 				i = i + result.getInt("xuefen");
 			}
			// 关闭声明和连接
			sql.close();
			con.close();

		} catch (java.lang.ClassNotFoundException e) {
			// 加载jdbc错误，所要用的驱动没找到
			e.printStackTrace();
			System.out.println("dfsdf"); 
			// 其他错误
		} catch (SQLException ex) {
			System.err.println("SQLException: " + ex.getMessage());
			// 显示数据库连接错误或者查询错误
		}
		System.out.println("xuefen "+i);
		return i;
	}
	
	public static Connection getConnection() throws SQLException,
	java.lang.ClassNotFoundException {
	//    取得连接的url
	String url = "jdbc:odbc:Component";
	//    加载SQLSERVER的jdbc驱动
	Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
	//    使用能访问SQLSERVER数据库的用户名sa
	String userName = "sa";
	//    使用口令
	String password = "123";
	//    打开数据库连接
	Connection con = DriverManager.getConnection(url, userName, password);
	return con;
	}
}