GreenDao配置以及使用

来源：互联网发布：数据库删除语句怎么写编辑：程序博客网时间：2024/06/08 20:05

在项目build最上面添加

apply plugin: 'org.greenrobot.greendao'

然后在项目build里在buildTypes里面配置greendao，，切记daoPackage一定要写自己工程的目录

 greendao {        schemaVersion 1        daoPackage 'com.example.greendao_lianxi.gen'        targetGenDir 'src/main/java'    }



然后添加greendao依赖
compile 'org.greenrobot:greendao:3.2.0'



然后在工程build里buildscript下配置，配置完记得编译才有下面的注解
mavenCentral()
classpath 'com.android.tools.build:gradle:3.0.0'


自己写实体类，定义自己需要的参数，记得注解
package com.example.greendao_lianxi;import org.greenrobot.greendao.annotation.Entity;import org.greenrobot.greendao.annotation.Id;import org.greenrobot.greendao.annotation.Property;/** * Created by Administrator on 2017/12/1. */@Entitypublic class Use {    @Id    private long id;    @Property(nameInDb = "name")    private String name;}


然后点击这个按钮会自动生成三个类

再定义一个类通过单例创建数据库

package com.example.greendao_lianxi;import android.app.Application;import android.database.sqlite.SQLiteDatabase;import com.example.greendao_lianxi.gen.DaoMaster;import com.example.greendao_lianxi.gen.DaoSession;/** * Created by Administrator on 2017/12/1. */public class Api extends Application{    //配置GreenDao    private static Api  myApi;    private DaoSession daoSession;    @Override    public void onCreate() {        super.onCreate();        myApi = this;        setDb();    }    //单例模式   public static Api getmyapi(){        return myApi;    }    private void setDb() {        //创建数据库名        DaoMaster.DevOpenHelper helper = new DaoMaster.DevOpenHelper(this, "bw,db", null);        //读取数据库        SQLiteDatabase database = helper.getWritableDatabase();        //        DaoMaster daoMaster = new DaoMaster(database);        //放入用户信息DaoSession        daoSession = daoMaster.newSession();    }    //返回daoSession    public DaoSession getDaoSession(){        return daoSession;    }}

然后在MainActivity里写增删改查方法

package com.example.greendao_lianxi1;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.view.View;import android.widget.Button;import android.widget.EditText;import android.widget.TextView;import android.widget.Toast;import com.example.greendao_lianxi1.gen.BeanDao;import com.example.greendao_lianxi1.gen.DaoSession;import java.util.List;public class MainActivity extends AppCompatActivity implements View.OnClickListener{    private EditText et_name;    private EditText et_xiu;    private BeanDao beanDao;    private TextView tv;    int a=1;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        Button bt_tian =  findViewById(R.id.bt_tian);        Button bt_shan =  findViewById(R.id.bt_shan);        Button bt_gai =  findViewById(R.id.bt_gai);        Button bt_cha =  findViewById(R.id.bt_cha);        tv = findViewById(R.id.tv);        et_name = findViewById(R.id.et_name);        et_xiu = findViewById(R.id.et_xiu);        bt_tian.setOnClickListener(this);        bt_shan.setOnClickListener(this);        bt_gai.setOnClickListener(this);        bt_cha.setOnClickListener(this);        //获取MyGreenDao_Api单例里面返回的方法        DaoSession daoSession = MyGreenDao_Api.getMyGreenDao_api().getDaoSession();        beanDao = daoSession.getBeanDao();    }    @Override    public void onClick(View view) {        switch (view.getId()){            //添加            case  R.id.bt_tian:                    Bean bean = new Bean(Long.valueOf(a++), et_name.getText().toString().trim());                    //添加方法                    beanDao.insert(bean);                Toast.makeText(this, "添加成功", Toast.LENGTH_SHORT).show();                break;            //删除            case  R.id.bt_shan:                //查询                Bean shanchu_id = beanDao.load(Long.valueOf(1));                //删除                beanDao.delete(shanchu_id);                Toast.makeText(this, "删除成功", Toast.LENGTH_SHORT).show();                break;                //修改            case  R.id.bt_gai:                //查找指定id                Bean xiugai_id = beanDao.load(Long.valueOf(2));                //输入修改内容                xiugai_id.setName(et_xiu.getText().toString().trim());                //修改方法                beanDao.update(xiugai_id);                Toast.makeText(this, "修改成功", Toast.LENGTH_SHORT).show();                break;            //查找            case  R.id.bt_cha:                //  load查询单个                //Bean load = beanDao.load(Long.valueOf(1));                //  loadAll查询全部                List<Bean> list = beanDao.loadAll();                String s="";                for (int i = 0; i < list.size(); i++) {                    s+=list.get(i).getName()+"/n";                }                tv.setText(s);                break;        }    }}

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