cddao.java

我做的第一个java MIS项目

package server.dao;

import java.sql.*;
import java.util.Vector;

import server.entity.*;
import server.entity.Time;

public class Cddao {

    private Connection con = null;
    private Connectionmanager cm = null;
    private PreparedStatement ps = null;
    private ResultSet rs = null;

    //检验检查客户借碟数量
    public boolean chk(Card card) {
        //初始化变量
        String testcardid = card.getcardid();
        int cdoutnum = 0;
        String dbusername = null;
        String dbuserpwd = null;
        //创建一个连接并得到查询结果
        cm = new Connectionmanager();
        con = cm.getconnection();
        try
        {
            ps = con.prepareStatement("select reccardid from record where reccardid=" +testcardid);
            rs = ps.executeQuery();
            while (rs.next()) {cdoutnum++;}
        } catch (SQLException ex) {return false;}
        //断开数据连接
        finally
        {
            cm.closeresultset(rs);
            cm.closestatement(ps);
            cm.closeconnection(con);
        }
        //判断并返回判断值
        if (cdoutnum >= Sysconfig.getcdoutmaxnum()) {return true;} else {return false;}
    }

    //检查碟片是否在铺
    public boolean chkcdexist(Cd cdtemp) {
        //初始化变量
        String testcdid = cdtemp.getcdid();
        int cdexist = 0;
        //创建一个连接并得到查询结果
        cm = new Connectionmanager();
        con = cm.getconnection();
        try {
            ps = con.prepareStatement("select cdexist from cd where cdid='" +testcdid + "'");
            rs = ps.executeQuery();
            rs.next();
            cdexist = rs.getInt(1);
        } catch (SQLException ex) {
            return false;
        }
        //断开数据连接
        finally {
            cm.closeresultset(rs);
            cm.closestatement(ps);
            cm.closeconnection(con);
        }
        //判断并返回判断值
        if (cdexist == 1) {
            return true;
        } else {
            return false;
        }
    }

    //检查碟片编号的有效性
    public boolean chkcdhas(Cd cdtemp) {
        //初始化变量
        String testcdid = cdtemp.getcdid();
        String cdhas;
        //创建一个连接并得到查询结果
        cm = new Connectionmanager();
        con = cm.getconnection();
        try {
            ps = con.prepareStatement("select cdid from cd where cdid='" +testcdid + "'");
            rs = ps.executeQuery();
            rs.next();
            cdhas = rs.getString(1);
        } catch (SQLException ex) {
            return false;
        }
        //断开数据连接
        finally {
            cm.closeresultset(rs);
            cm.closestatement(ps);
            cm.closeconnection(con);
        }
        //判断并返回判断值
        if (!cdhas.equals("")) {
            return true;
        } else {
            return false;
        }
    }

    //显示归还碟片时信息
    public Vector showcdininf(Cd cdtemp,int isoverterm) {
        //初始化变量
        String testcdid = cdtemp.getcdid();
        Vector cdininf=new Vector();
        //创建一个连接并得到查询结果
        cm = new Connectionmanager();
        con = cm.getconnection();
        try {
            //得到归还碟片的相关资料
            ps = con.prepareStatement("select cdname,cdtype,cdmtype from cd where cdid='" +testcdid + "'");
            rs = ps.executeQuery();
            rs.next();
            cdininf.addElement(rs.getString(1));
            cdininf.addElement(rs.getString(2));
            cdininf.addElement(rs.getString(3));
            //得到归还碟片的帐户卡号

            ps = con.prepareStatement("select cardid from card where cardid=(select reccardid from record where recid='"+temp.getrecid()+"')");
            rs = ps.executeQuery();
            rs.next();
            String cardidt=rs.getString(1);
            cdininf.addElement(cardidt);
            //得到归还碟片的帐户名字
            ps = con.prepareStatement("select cardusername from card where cardid='"+cardidt+"'");
            rs = ps.executeQuery();
            rs.next();
            cdininf.addElement(rs.getString(1));
            //如果超期，得到罚金
            if(isoverterm==1)
            {
                String strtemp="select pntmomey from penalty where pntrecid='"+temp.getrecid()+"'";
                ps = con.prepareStatement(strtemp);
                rs=ps.executeQuery();
                rs.next();
                cdininf.addElement(rs.getFloat(1)+"");
            }
        } catch (SQLException ex) {}
        //断开数据连接
        finally
        {
            cm.closeresultset(rs);
            cm.closestatement(ps);
            cm.closeconnection(con);
        }
        return cdininf;
    }

    //显示借出碟片时信息
    public Vector showcdoutinf(Cd cdtemp) {
        //初始化变量
        String testcdid = cdtemp.getcdid();
        Vector cdoutinf=new Vector();
        //创建一个连接并得到查询结果
        cm = new Connectionmanager();
        con = cm.getconnection();
        try {
            //得到借出碟片的相关资料
            ps = con.prepareStatement("select cdname,cdtype,cdmtype from cd where cdid='" +testcdid + "'");
            rs = ps.executeQuery();
            rs.next();
            cdoutinf.addElement(rs.getString(1));
            cdoutinf.addElement(rs.getString(2));
            cdoutinf.addElement(rs.getString(3));
            //得到借出碟片的帐户名字
            String getcdoutusername="select cardusername from card where cardid=(select reccardid from record where reccdid='" +testcdid + "' and recendtime='1970-01-01')";
            ps = con.prepareStatement(getcdoutusername);
            rs = ps.executeQuery();
            rs.next();
            cdoutinf.addElement(rs.getString(1));
            } catch (SQLException ex) {}
            //断开数据连接
            finally
            {
               cm.closeresultset(rs);
               cm.closestatement(ps);
               cm.closeconnection(con);
            }
        return cdoutinf;
    }

    //得到最大的cd编号
    public int getmaxcdid() {
        //初始化变量
        int maxcdid=0;
        int t=0;
        //创建一个连接并得到查询结果
        cm = new Connectionmanager();
        con = cm.getconnection();
        try
        {
            ps = con.prepareStatement("select max(cdid) from cd");
            rs = ps.executeQuery();
            while (rs.next())
            {
                t=rs.getInt(1);
                if (maxcdid<t)
                {maxcdid=t;}
            }
        } catch (SQLException ex) {}
        //断开数据连接
        finally
        {
            cm.closeresultset(rs);
            cm.closestatement(ps);
            cm.closeconnection(con);
        }
        //返回值
        return maxcdid;
    }

}