GreenDao简单的增删改查

1，在项目的build.grade中文件里加入一行代码
dependencies{
classpath ‘org.greenrobot:greendao-gradle-plugin:3.2.0’
}

2,在app的build.grade里面最上面加上代码 apply plugin: ‘org.greenrobot.greendao’
3：在app的build.grad里面Android{}里加上代码

 greendao{
 schemaVersion 1          //指定数据库schema版本号，迁移等操作会用到包名是活的这是变动的
 daoPackage 'soexample.umeng.com.greendaodemo.mydao'        //切换为你自己的包名
 targetGenDir 'src/main/java'         //生成数据库文件的目录
}

4，导入依赖
implementation ‘org.greenrobot:greendao:3.2.2’

5，写一个实体类 并添加字段

@Entity
public class Person {

    @Id(autoincrement = true)        //主键自增
    private Long id;
    private String name;
    private String sex;
    }

6，点击make project得到三个class文件
通过锤子（make Project）

• 1:DaoMaster
• 2:DaoSession
• 3:PersonDao

7,创建一个类 继承Application

public class MyApp extends Application {

    private static DaoSession daoSession;

    @Override
    public void onCreate() {
        super.onCreate();
        initgreendao();
    }

    private void initgreendao() {
        DaoMaster.DevOpenHelper openHelper=new DaoMaster.DevOpenHelper(this,"zpp.db");
        SQLiteDatabase writableDatabase = openHelper.getWritableDatabase();
        DaoMaster master=new DaoMaster(writableDatabase);
        daoSession = master.newSession();
    }

    public  static DaoSession getDaoSession(){
        return daoSession;
    }
}

不要忘记在manifest中
android:name=".MyApp"
8，最后增删改查 四个按钮

public class MainActivity extends AppCompatActivity {

    @BindView(R.id.zeng)
    Button zeng;
    @BindView(R.id.shan)
    Button shan;
    @BindView(R.id.gai)
    Button gai;
    @BindView(R.id.cha)
    Button cha;
    @BindView(R.id.tv)
    TextView tv;
    private PersonDao mDao;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.bind(this);
        mDao = MyApp.getDaoSession().getPersonDao();


    }

    @OnClick({R.id.zeng, R.id.shan, R.id.gai, R.id.cha})
    public void onViewClicked(View view) {
        switch (view.getId()) {
            case R.id.zeng:
                insertstr();
                break;
            case R.id.shan:
                delStr();
                break;
            case R.id.gai:
                updata();
                break;
            case R.id.cha:
                selectstr();
                break;
        }
    }

    //改
    private void updata() {
        Person person = mDao.load(3l);
        person.setName("张三");
        person.setSex("女");
        mDao.update(person);

    }


    //删
    private void delStr() {
        mDao.deleteByKey(1l);
        Toast.makeText(MainActivity.this,"删除成功！",Toast.LENGTH_LONG).show();
    }

    //查
    private void selectstr() {
        tv.setText("");
        List<Person> people = mDao.loadAll();
        tv.setText(people.toString());
    }


    //增
    private void insertstr() {
        Person person = new Person("哈哈哈", "男");
        long insert = mDao.insert(person);
        if (insert > 0) {
            Toast.makeText(MainActivity.this, "添加成功!", Toast.LENGTH_LONG).show();
        }
    }


}