数据库的Util

最新推荐文章于 2024-11-28 18:44:52 发布

CruelRui

最新推荐文章于 2024-11-28 18:44:52 发布

阅读量399

点赞数

CC 4.0 BY-SA版权

本文链接：https://blog.youkuaiyun.com/CruleRui/article/details/89300975

本文介绍了一个用于管理商品列表的实用工具类，通过GreenDAO框架实现商品数据的增删查改操作，包括添加、查询所有、删除指定商品及全部商品的功能。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;

import com.bw.app0413.bean.CommodityList;
import com.bw.app0413.greendao.CommodityListDao;
import com.bw.app0413.greendao.DaoMaster;

import java.util.ArrayList;
import java.util.List;

/**
 * 作者：ww
 * <p>
 * 邮箱：
 * <p>
 * 时间:on 2019/4/14 19:03
 */
public class CommodityListUtil {
    private CommodityListDao dao;

    private CommodityListUtil(){};
    private static CommodityListUtil mCommodityListUtil=null;

    public static CommodityListUtil getmCommodityListUtil(){
        synchronized (CommodityListUtil.class){
            if (mCommodityListUtil==null){
                mCommodityListUtil=new CommodityListUtil();
            }
        }
        return mCommodityListUtil;
    }

    //初始化控件
    public void init(Context context){
        DaoMaster.DevOpenHelper helper=new DaoMaster.DevOpenHelper(context,"commodityList");
        SQLiteDatabase db = helper.getWritableDatabase();
        DaoMaster daoMaster = new DaoMaster(db);
        dao = daoMaster.newSession().getCommodityListDao();
    }

    //添加
    public void add(CommodityList list){
        List<CommodityList> loadAll = dao.loadAll();
        for (int i=0;i<loadAll.size();i++){
            CommodityList commodityList = loadAll.get(i);
            if (loadAll.get(i).getCommodityId()==list.getCommodityId()){
                dao.delete(commodityList);
            }
        }
        dao.insert(list);
    }

    //查询所有
    public List<CommodityList> loadAll(){
        List<CommodityList> commodityLists = dao.loadAll();

        List<CommodityList> Tadd = new ArrayList<>();
        for (int i=0;i<commodityLists.size();i++){
            CommodityList list = commodityLists.get(i);
            Tadd.add(0,list);
        }
        return Tadd;
    }

    //删除所有
    public void deleteAll(){
        dao.deleteAll();
    }

}