determine.java

这是书上的<java毕业设计指南与项目实践>的第6章:基于JSP+JavaBean+Servlet的课程管理系统,供大家参考

package com.course;
import java.sql.*;

public class determine{
				                             
  //根据教师ID查询班级和课程信息
  public ResultSet getClass(String tea_id){
   	String sql="select classes.id,course.name  "+
				"from classes,course "+
				"where course.id=classes.cour_id "+
				"and classes.tea_id='"+tea_id+"' ";
   	           sqlBean sqlbean = new sqlBean(); 
           ResultSet rs = sqlbean.executeQuery(sql);
           return rs;
   	
   	}
   	
   	
   	//根据班级ID查询学生的具体信息
  public ResultSet getStudents(String class_id){
  	String sql="select student.id,name ,department,sex,mark,e_mail,tel "+
				"from student,enrol,classes "+
				"where student.id=enrol.stu_id "+
				"and enrol.accept='0' "+
				"and classes.id=enrol.class_id "+
				"and classes.id='"+class_id+"' ";
           sqlBean sqlbean = new sqlBean(); 
           ResultSet rs = sqlbean.executeQuery(sql);
           return rs; 	
  	}
  	
  	  public ResultSet getStudents2(String class_id){
  	String sql="select student.id,name ,department,sex,mark,e_mail,tel "+
				"from student,enrol,classes "+
				"where student.id=enrol.stu_id "+
				"and enrol.accept='1' "+
				"and enrol.score='0' "+
				"and classes.id=enrol.class_id "+
				"and classes.id='"+class_id+"' ";
           sqlBean sqlbean = new sqlBean(); 
           ResultSet rs = sqlbean.executeQuery(sql);
           return rs; 	
  	}
  	
  //根据学生ID和班级ID,进行数据库更新操作，用来更改标识位，表示学生选课成功	
  public int enrol(String stu_id,String class_id){
  	int num=0;
  	String sql="update enrol set accept=1  "+
               "where stu_id='"+stu_id+"' "+
                "and class_id='"+class_id+"'  ";
  	           sqlBean db = new sqlBean(); 
               num=db.executeInsert(sql);
           return num;
  	
  	}
  	//给选课的学生打分
  public int marking(String stu_id,String class_id,String score){
  	int num=0;
  	String sql="update enrol "+
			"set score='"+score+"' "+
			"where stu_id='"+stu_id+"' "+
			"and class_id='"+class_id+"' ";
			 sqlBean db = new sqlBean(); 
             num=db.executeInsert(sql);
             return num;
  	
  	}
  	//修改学生成绩	 	        
	public int addMark(String stu_id,String class_id){
		int num=0;
		String sql="update student "+
					"set student.mark=student.mark+course.mark "+
					"from student,course,classes "+
					"where student.id='"+stu_id+"' "+
					"and course.id=classes.cour_id "+
					"and classes.id='"+class_id+"' ";
             sqlBean db = new sqlBean(); 
             num=db.executeInsert(sql);
             return num;
		
		}	                       
	}