GreenDao简单操作

配置数据库 DBhelper

public class DbHelper {
    private static volatile DbHelper instance;
    private final DaoSession daoSession;

    private DbHelper(String name, Context context){
        //初始化数据库的一些配置
        DaoMaster.DevOpenHelper helper = new DaoMaster.DevOpenHelper(context, name, null);
        //获取数据库操作对象
        SQLiteDatabase db = helper.getWritableDatabase();
        //获取DaoMaster对象
        DaoMaster daoMaster = new DaoMaster(db);
        //获取DaoSession对象
        daoSession = daoMaster.newSession();
    }
    public static  DbHelper getInstance(String name, Context context){
        if (instance==null){
            synchronized (DbHelper.class){
                if (instance==null){
                    instance=new DbHelper(name, context);
                }
            }
        }
        return instance;
    }
    public UserDao getUserDao(){
        return daoSession.getUserDao();
    }
}

对数据的增,删,改,查

public class MainActivity extends AppCompatActivity {

    @BindView(R.id.et_userid)
    EditText etUserid;
    @BindView(R.id.et_username)
    EditText etUsername;
    @BindView(R.id.btn_add)
    Button btnAdd;
    @BindView(R.id.btn_del)
    Button btnDel;
    @BindView(R.id.btn_select)
    Button btnSelect;
    @BindView(R.id.tv_show)
    TextView tvShow;
    @BindView(R.id.btn_update)
    Button btnUpdate;
    private UserDao dao;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.bind(this);
        dao = DbHelper.getInstance("user", this).getUserDao();
    }

    @OnClick({R.id.btn_add, R.id.btn_del, R.id.btn_update,R.id.btn_select})
    public void onViewClicked(View view) {
        switch (view.getId()) {
            //添加
            case R.id.btn_add:
                Long id = Long.valueOf(etUserid.getText().toString().trim());
                String name = etUsername.getText().toString().trim();
                    User user = new User();
                    user.setId(id);
                    user.setName(name);
                    long count = dao.insert(user);

                break;
            //删除
            case R.id.btn_del:
                User user1 = new User();
                user1.setId(2L);
                dao.delete(user1);
                break;
            //修改数据
            case R.id.btn_update:
                //根据id更改数据
                User user2 = new User(4L,"范杰");
                dao.update(user2);
                break;
            //查询 n
            case R.id.btn_select:
                //查询所有数据
//                List<User> users = dao.loadAll();
                tvShow.setText("");
//                for(int i=0;i<users.size();i++){
//                    User user1 = users.get(i);
//                    //展示
//                    tvShow.append(user1.getId()+user1.getName()+"=====");
//                }
                //根据条件查询(String)
//                User user1 = dao.queryBuilder().where(UserDao.Properties.Name.eq("李四")).unique();
//                tvShow.setText(user1.toString());
                //在多条同时满足条件时不能查询
//                User user1 = dao.queryBuilder().where(UserDao.Properties.Id.eq(2),UserDao.Properties.Name.eq("李四")).unique();
                //在多条同时满足条件时可以查询
                List<User> list = dao.queryRaw("where name=?", "李四");
                tvShow.append(list.toString());
                break;
        }
    }
}

实体类要加注解生成gen文件

@Entity
public class User {
    @Id
    private Long id;
    private String name;
}