teacher_achievementdao.java

可以实现在线考试

package dao;

import java.sql.*;
import java.util.ArrayList;
import vo.*;

public class Teacher_achievementDAO 
{
	private Connection conn = null;
	private Statement state = null;
	private ResultSet rs = null;
	
	//根据科目名称进行查询_显示出此科目的全部学生
	public ArrayList findByCname(String cname)
	{
		ArrayList array = new ArrayList();
		conn = dao.Tools.getConnection();
		try {
			state = conn.createStatement();
			rs = state.executeQuery("select * from subject c,grade g,student_base s where c.cname='"+cname+"' and c.cid = g.cid and s.sid = g.sid");
			while(rs.next())
			{
				Subject_Studentbase_GradeVO ssgvo = new Subject_Studentbase_GradeVO();
				ssgvo.setCid(rs.getInt("cid"));
				ssgvo.setCname(rs.getString("cname"));
				ssgvo.setSid(rs.getInt("sid"));
				ssgvo.setSname(rs.getString("sname"));
				ssgvo.setRid(rs.getInt("rid"));
				ssgvo.setOverdate(rs.getString("overdate"));
				ssgvo.setTotalanswer(rs.getInt("totalanswer"));
				ssgvo.setRightanswer(rs.getInt("rightanswer"));
				ssgvo.setWronganswer(rs.getInt("wronganswer"));
				ssgvo.setScore(rs.getInt("score"));
				array.add(ssgvo);
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			try {
				if(rs != null)
					rs.close();
				if(state != null)
					state.close();
				if(conn != null)
					conn.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		return array;
	}
	

	
	//按学号查询
	public Subject_Studentbase_GradeVO findbySid(int sid)
	{
		Subject_Studentbase_GradeVO ssgvo = null;
		conn = Tools.getConnection();
		try {
			state = conn.createStatement();
			rs = state.executeQuery("select * from subject c,grade g,student_base s where s.sid='"+sid+"' and c.cid = g.cid and s.sid = g.sid");
			while(rs.next())
			{
				ssgvo = new Subject_Studentbase_GradeVO();
				ssgvo.setCid(rs.getInt("cid"));
				ssgvo.setCname(rs.getString("cname"));
				ssgvo.setSid(rs.getInt("sid"));
				ssgvo.setSname(rs.getString("sname"));
				ssgvo.setRid(rs.getInt("rid"));
				ssgvo.setOverdate(rs.getString("overdate"));
				ssgvo.setTotalanswer(rs.getInt("totalanswer"));
				ssgvo.setRightanswer(rs.getInt("rightanswer"));
				ssgvo.setWronganswer(rs.getInt("wronganswer"));
				ssgvo.setScore(rs.getInt("score"));
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			try {
				if(rs != null)
					rs.close();
				if(state != null)
					state.close();
				if(conn != null)
					conn.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		return ssgvo;
	}
	//按姓名查询
	public Subject_Studentbase_GradeVO findbySname(String sname)
	{
		Subject_Studentbase_GradeVO ssgvo = null;
		conn = Tools.getConnection();
		try {
			state = conn.createStatement();
			rs = state.executeQuery("select * from subject c,grade g,student_base s where s.sname='"+sname+"' and c.cid = g.cid and s.sid = g.sid");
			while(rs.next())
			{
				ssgvo = new Subject_Studentbase_GradeVO();
				ssgvo.setCid(rs.getInt("cid"));
				ssgvo.setCname(rs.getString("cname"));
				ssgvo.setSid(rs.getInt("sid"));
				ssgvo.setSname(rs.getString("sname"));
				ssgvo.setRid(rs.getInt("rid"));
				ssgvo.setOverdate(rs.getString("overdate"));
				ssgvo.setTotalanswer(rs.getInt("totalanswer"));
				ssgvo.setRightanswer(rs.getInt("rightanswer"));
				ssgvo.setWronganswer(rs.getInt("wronganswer"));
				ssgvo.setScore(rs.getInt("score"));
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			try {
				if(rs != null)
					rs.close();
				if(state != null)
					state.close();
				if(conn != null)
					conn.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		return ssgvo;
	}
}