2023年2月23号

package qsap;
public class qsap {
    String id;
    String name;
    String place;

    public qsap(String id,String name,String place)
    {
        this.id=id;
        this.name=name;
        this.place=place;
    }


    public qsap(String name,String place)
    {

        this.name=name;
        this.place=place;
    }

    public void setId(String id) {
        this.id=id;
    }

    public void setName(String name) {
        this.name=name;
    }

    public void setPlace(String place) {
        this.place=place;
    }


    public String getId() {
        return id;
    }

    public String getName() {
        return name;
    }

    public String getPlace() {
        return place;
    }
}

package Dao;
import qsap.qsap;
import util.DBUtil;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;
public class Dao {

    public boolean add(qsap qsap) {
        String sql = "insert into qsap(id,name,place) values('" + qsap.getId() + "','" + qsap.getName() + "','" + qsap.getPlace()  + "')";
        Connection conn = DBUtil.getConn();
        Statement state = null;
        boolean f = false;
        int a = 0;
        try {
            state = conn.createStatement();
            a = state.executeUpdate(sql);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(state, conn);
        }

        if (a > 0) {
            f = true;
        }
        return f;
    }
 
    public boolean leibie(String id) {
        boolean flag = false;
        if(id.length()>20)return true;
        String sql = "select zhuti from qsap where id = '" + id + "'";
        Connection conn = DBUtil.getConn();
        Statement state = null;
        ResultSet rs = null;
        try {
            state = conn.createStatement();
            rs = state.executeQuery(sql);
            while (rs.next()) {
                flag = true;
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(rs, state, conn);
        }
        return flag;
    }

    public List<qsap> list() {
        String sql = "select * from qsap";
        List<qsap> list = new ArrayList<>();
        Connection conn = DBUtil.getConn();
        Statement state = null;
        ResultSet rs = null;

        try {
            state = conn.createStatement();
            rs = state.executeQuery(sql);
            qsap bean = null;
            while (rs.next()) {
                String id = rs.getString("id");
                String name = rs.getString("name");
                String place = rs.getString("place");
                bean = new qsap(id,name,place);
                list.add(bean);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(rs, state, conn);
        }

        return list;
    }



    public boolean update(qsap qsap,String id) {
        String sql = " UPDATE qsap SET id='" + qsap.getId() + "', name ='" + qsap.getName()+ "' ;";
        boolean f = false;
        Connection conn = DBUtil.getConn();
        Statement state = null;
        int a = 0;

        try {
            state = conn.createStatement();
            a= state.executeUpdate(sql);
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(state, conn);
        }
        if (a > 0) {
            f = true;
        }
        return f;


    }
  
    public qsap getByName(String id) {
        String sql = "select * from qsap where id ='" + id + "'";
        Connection conn = DBUtil.getConn();
        Statement state = null;
        ResultSet rs = null;
        qsap qsap= null;

        try {
            state = conn.createStatement();
            rs = state.executeQuery(sql);
            while (rs.next()) {
                String name = rs.getString("name");
                String place = rs.getString("place");
                qsap = new qsap(name,place);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(rs, state, conn);
        }

        return qsap;
    }


    public  List<qsap> getdel(String id)
    { String sql = "select * from qsap where id ='" + id + "'";
        List<qsap> list = new ArrayList<>();
        Connection conn = DBUtil.getConn();
        Statement state = null;
        ResultSet rs = null;
        qsap qsap= null;

        try {
            state = conn.createStatement();
            rs = state.executeQuery(sql);
            while (rs.next()) {
                String name = rs.getString("name");
                String place = rs.getString("place");
                qsap = new qsap(id,name,place);
                list.add(qsap);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(rs, state, conn);
        }
        return list;
    }

}

 今天完成了大部分的代码，目标是完成一个简单的寝室管理系统包括学生学号，学生姓名，学生寝室。在明天就应该能完成了，今天学习时间为两个小时。