Android 数据库框架GreenDao实战使用

1.添加记录(SQLite 增)

2.删除记录(SQLite 删)

3.修改记录(SQLite 改)

4.查询记录(SQLite 查)

<1> DAO查询

<2>QueryBuilder查询

<4>Query重复查询

<5>常用的查询方法含义

<6>调试技巧

.5.java后台代码

新建2个java类(HMROpenHelper、MyGreenDaoApplication)

(1)HMROpenHelper代码

package com.example.lucky.mygreendaotest;

import android.content.Context;

import android.database.sqlite.SQLiteDatabase;

import com.example.lucky.mygreendaotest.gen.DaoMaster;

//数据库创建工具类

public class HMROpenHelper extends DaoMaster.OpenHelper {

    //构造函数，参数2 name为数据库名称

    public HMROpenHelper(Context context, String name, SQLiteDatabase.CursorFactory factory) {

        super(context, name, factory);

    }

}

(2)MyGreenDaoApplication

package com.example.lucky.mygreendaotest;

import android.app.Application;

import android.database.sqlite.SQLiteDatabase;

import com.example.lucky.mygreendaotest.gen.DaoMaster;

import com.example.lucky.mygreendaotest.gen.DaoSession;

/*注意：MyGreenDaoApplication类继承Application,需要在AndroidManifest.xml文件中进行相关设置

android:name=".MyGreenDaoApplication"

MyGreenDaoApplication类的作用是封装数据库对象*/

public class MyGreenDaoApplication extends Application {

    private SQLiteDatabase db;   //SQLiteDatabase数据库对象

    private DaoMaster daoMaster; //daoMaster对象

    private DaoSession daoSession; //daoSession对象

    public  static MyGreenDaoApplication instances; //声明本类的实例对象

    @Override

    public void onCreate() {

        super.onCreate();

        instances=this; //给实例对象赋值

        setDatabase();

    }

    private void setDatabase() {

        //创建数据库

        HMROpenHelper hmrOpenHelper=new HMROpenHelper(this,"mydb1",null);

        db=hmrOpenHelper.getWritableDatabase(); //获取数据库对象

        daoMaster=new DaoMaster(db);  //获取DaoMaster对象

        daoSession=daoMaster.newSession();

    }

    //获取instances 对象

    public  static MyGreenDaoApplication getInstances(){

        return instances;

    }

    //获取daoSession对象

    public DaoSession getDaoSession(){

        return daoSession;

    }

    public SQLiteDatabase getDb(){

        return db;

    }

}

(2)MainActivity代码

package com.example.lucky.mygreendaotest;

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.util.Log;

import android.widget.TextView;

import com.example.lucky.mygreendaotest.gen.UserDao;

import org.greenrobot.greendao.query.Query;

import org.greenrobot.greendao.query.QueryBuilder;

import java.io.BufferedReader;

import java.io.FileNotFoundException;

import java.io.FileReader;

import java.io.IOException;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.io.Reader;

import java.util.ArrayList;

import java.util.List;

public class MainActivity extends AppCompatActivity {

    private TextView tv_result;

    private UserDao userDao;

    private List<User> userList;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        tv_result=findViewById(R.id.tv_result);

        userList=new ArrayList<>();

        QueryBuilder.LOG_SQL=true;     //显示SQL语句(可在控制台的Run窗口中看到SQL语句)

        QueryBuilder.LOG_VALUES=true;  //显示SQL语句的值

        userDao=MyGreenDaoApplication.getInstances().getDaoSession().getUserDao();

        userDao.deleteAll(); //清空表中的所有数据

//        insertOneRecord(); //插入一条数据

//        queryOneByName();  //根据姓名查询记录

        insertManyRecord(); //插入多条记录

//        deleteByName();     //根据姓名删除记录

//        userDao.deleteByKey((long)12); //通过主键值删除记录

//        updateUser();    //修改数据表的数据

//        queryList();     //查询多条记录

//        loadOneById();

//        queryMany();

        queryRepeat();

        //在控制台输出语句

//        System.out.println("like");  //方式1

//        Log.d("002","linda");//方式2

        try {

            InputStream input=getResources().openRawResource(R.raw.user);//xiaohuat是我的文件名，这里应该根据具体文件更改

            Reader reader=new InputStreamReader(input);

            BufferedReader br=new BufferedReader(reader);

            String str;

            while ((str=br.readLine())!=null){

                System.out.println(str);

            }

        } catch (FileNotFoundException e) {

            e.printStackTrace();

        } catch (IOException e) {

            e.printStackTrace();

        }

    }

    //插入一条数据记录

    private void insertOneRecord(){

        User user=new User(); //实例化实体类对象

        user.setName("lucky");

        user.setUsercode("007");

        user.setUserAddress("天台县");

        userDao.insert(user);

    }

    //插入多条数据记录

    private void insertManyRecord(){

        List<User> userList=new ArrayList<>();

        User user1=new User();

        user1.setName("linda");

        user1.setUsercode("001");

        user1.setUserAddress("杭州");

        User user2=new User();

        user2.setName("jack");

        user2.setUsercode("002");

        user2.setUserAddress("苏州");

        User user3=new User();

        user3.setName("lily");

        user3.setUsercode("003");

        user3.setUserAddress("南京");

        User user4=new User();

        user4.setName("pink");

        user4.setUsercode("004");

        user4.setUserAddress("湖州");

        userList.add(user1);

        userList.add(user2);

        userList.add(user3);

        userList.add(user4);

        userDao.insertInTx(userList);

    }

    //单条数据查询

    private void queryOneByName(){

        User user=userDao.queryBuilder().where(UserDao.Properties.Name.eq("lucky")).build().unique();

        if(user!=null){

            tv_result.setText("添加一条记录的结果为："+"\n\n"+"id:"+user.getId()

            +"\n"+"姓名："+user.getName()

            +"\n"+"地址"+user.getUserAddress()

            +"\n"+"用户编号："+user.getUsercode());

        }

    }

    private void queryList(){

        String resultStr="显示结果为："+"\n\n";

        List<User> userList=userDao.loadAll();

        int i=0;

        for (User user : userList) {

            i=i+1;

            resultStr=resultStr+"第"+i+"条记录的结果："+"id:"+user.getId()+

                    "\n"+"姓名："+user.getName()+"\n"+"地址："+user.getUserAddress()+"\n\n";

        }

        tv_result.setText(resultStr);

    }

    //根据姓名删除记录

    private void deleteByName(){

        QueryBuilder queryBuilder=userDao.queryBuilder();

        List<User> userList=queryBuilder.where(UserDao.Properties.Name.eq("linda")).list();

        for (User user : userList) {

            userDao.delete(user);

        }

    }

    private void updateUser(){

        //注意：一个实体类对象，相当于数据表中的一条记录

        User user=userDao.queryBuilder().where(UserDao.Properties.Name.eq("linda")).build().unique(); //查询数据表中姓名为linda的一条记录

        user.setUserAddress("上海");

        userDao.update(user); //更新数据表中的数据

    }

    //查询一条记录

    private void loadOneById(){

        User user= null;

        try {

            user = userDao.load((long) 15);

        } catch (Exception e) {

            e.printStackTrace();

        }

        tv_result.setText("Load一条记录的结果：\n"+"id:"+user.getId()+"\n姓名："+user.getName()+

        "\n地址："+user.getUserAddress());

    }

    //查询多条语句

    private void queryMany(){

        QueryBuilder queryBuilder=userDao.queryBuilder();

//        挑选名字中带有"in"的数据，并按降序排列

//        List<User> userList=queryBuilder.where(UserDao.Properties.Name.like("%in%"))

//                .orderDesc(UserDao.Properties.Id).list();

        List<User> userList=queryBuilder.where(UserDao.Properties.Name.like("%in%"),

                UserDao.Properties.UserAddress.eq("杭州")).list();

        queryResultShow(userList);

    }

    private void queryResultShow(List<User> userList) {

        if(userList!=null){

            String resultStr="查询结果为："+"\n\n";

            int i=0;

            for (User user : userList) {

                i=i+1;

                resultStr=resultStr+"第"+i+"条记录为：\n"+"id:"+user.getId()+"\n姓名："+user.getName()+

                        "\n地址："+user.getUserAddress()+"\n\n";

                tv_result.setText(resultStr);

            }

        }

    }

    private void queryRepeat(){

        Query query=userDao.queryBuilder().where(UserDao.Properties.Name.like("%in%"),

                UserDao.Properties.UserAddress.like("湖%")).build();

        query.setParameter(0,"%il%");

        query.setParameter(1,"%京");

        List<User> userList=query.list();

        queryResultShow(userList);

    }

}

巴特西

Android 数据库框架GreenDao实战使用

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