xUtils3.3.x数据库操作实例

xUtils是国人开发的一款功能丰富的Android开发框架，主要包括网络请求、图片加载、数据库操作等模块，本章主要介绍xUtils3.3.x在数据库方面的使用。

要使用xUtils，需要首先在Application或主Activity中进行xUtils初始化，我的xUtils3.3.x的初始化和数据库的配置都是在Application中进行的，具体代码如下：

import android.app.Application;import android.content.SharedPreferences;import android.os.Environment;import android.os.storage.StorageManager;import android.util.Log;import com.lnint.mediaplayer.utils.Constants;import org.xutils.DbManager;import org.xutils.x;import java.io.File;import java.lang.reflect.Method;/** * xUtils3.3应用demo * Created by wangpf on 2017/7/1. */public class MyApplication extends Application {    private DbManager.DaoConfig daoConfig;    private static MyApplication mInstance = null;    public DbManager.DaoConfig getDaoConfig() {        return daoConfig;    }    @Override    public void onCreate() {        super.onCreate();        mInstance = this;        x.Ext.init(this);        x.Ext.setDebug(BuildConfig.DEBUG);        String rootPath = MyApplication.getExternalStoragePath();        File dbFile = new File(rootPath + "/media/db/");        daoConfig = new DbManager.DaoConfig()                .setDbDir(dbFile)                .setDbName("media_dbs")//创建数据库的名称                .setDbVersion(1)//数据库版本号                .setDbUpgradeListener(new DbManager.DbUpgradeListener() {                    @Override                    public void onUpgrade(DbManager db, int oldVersion, int newVersion) {                        // db.addColumn(...);                        // db.dropTable(...);                        // ...                    }                });//数据库更新操作    }......

我们以保存并查询视频文件的播放历史为例，重点讲解对表sys_play_his的增删改查操作。

由于xUtils是一个ORM框架，所以第一步工作就是基于表sys_play_his创建实体，具体代码如下：

实体BaseEntity

import org.xutils.db.annotation.Column;/** * 实体BaseEntity * Created by wangpf on 2016/11/8. */public class BaseEntity {    //id    @Column(name = "id", isId = true)    private int id;    public int getId() {        return id;    }    public void setId(int id) {        this.id = id;    }}

数据库操作实体

import org.xutils.db.annotation.Column;import org.xutils.db.annotation.Table;import java.util.Date;/** * 保存媒体文件播放历史 * Created by wangpf on 2017/7/21. */@Table(name = "sys_play_his")public class PlayHisEntity extends BaseEntity {    //文件名    @Column(name = "fileName")    private String fileName;    //播放开始时间    private Date startTime;    //播放结束时间    @Column(name = "endTime")    private Date endTime;    //广告机编号    @Column(name = "equipNo")    private String equipNo;    //固件版本号    @Column(name = "firmware")    private String firmware;    public Date getStartTime() {        return startTime;    }    public void setStartTime(Date startTime) {        this.startTime = startTime;    }    public Date getEndTime() {        return endTime;    }    public void setEndTime(Date endTime) {        this.endTime = endTime;    }    ......}

准备工作做好之后，就可以对数据库进行操作，具体操作如下：

（1）数据插入

DbManager db = x.getDb(((MyApplication)getApplicationContext()).getDaoConfig());                try {                    PlayHisEntity entity = new PlayHisEntity();                    entity.setFileName("20170803120203.mp4");                    entity.setEndTime(new Date());                    entity.setFirmware("4.4.4");                    db.saveBindingId(entity);                }catch (DbException e) {                    e.printStackTrace();                }

（2）数据删除

DbManager db = x.getDb(MyApplication.getInstance().getDaoConfig());        try {            Date date = DateUtils.getLastDay(30);            db.delete(PlayHisEntity.class, WhereBuilder.b("endTime","<=",date));        }catch (DbException e) {            e.printStackTrace();        }

（3）数据查询

DbManager db = x.getDb(MyApplication.getInstance().getDaoConfig());        try {            if(StringUtils.isNotEmpty(playHisEntity.getFileName())) {//根据文件名查询                List<DbModel> dbModels = new ArrayList<DbModel>();                dbModels = db.selector(PlayHisEntity.class)                        .where("fileName","like","%"+playHisEntity.getFileName()+"%")                        .groupBy("fileName")                        .select("fileName", "count(fileName) as count").findAll();                List<VideoPlayEntity> playList = new ArrayList<VideoPlayEntity>();                for(DbModel dbModel : dbModels) {                    VideoPlayEntity entity = new VideoPlayEntity();                    entity.setName(dbModel.getString("fileName"));                    entity.setNum(dbModel.getInt("count"));                    playList.add(entity);                }            }else if(playHisEntity.getStartTime() != null && playHisEntity.getEndTime() != null) {//根据时间查询                List<DbModel> dbModels = db.selector(PlayHisEntity.class)                        .where("endTime","between",new Date[]{playHisEntity.getStartTime(), playHisEntity.getEndTime()})                        .groupBy("fileName")                        .select("fileName", "count(fileName) as count").findAll();                List<VideoPlayEntity> playList = new ArrayList<VideoPlayEntity>();                for(DbModel dbModel : dbModels) {                    VideoPlayEntity entity = new VideoPlayEntity();                    entity.setName(dbModel.getString("fileName"));                    entity.setNum(dbModel.getInt("count"));                    playList.add(entity);                }            }        }catch (DbException e) {            e.printStackTrace();        }