1.引入greendao
首先在project的gradle文件中引入greenDAO插件:
classpath 'org.greenrobot:greendao-gradle-plugin:3.1.0'
然后在module的gradle文件中添加greenDAO的插件,并引入相关类库:
apply plugin: 'org.greenrobot.greendao'
compile 'org.greenrobot:greendao:3.1.0'
2.数据库初始化:
数据库引入成功后,在使用之前,我们还得先来创建一个实体类:
@Entity public class User { @Id private Long id; @Property(nameInDb = "USERNAME") private String username; @Property(nameInDb = "NICKNAME") private String nickname; }
数据库初始化:
DaoMaster.DevOpenHelper devOpenHelper = new DaoMaster.DevOpenHelper(getApplicationContext(), "lenve.db", null); DaoMaster daoMaster = new DaoMaster(devOpenHelper.getWritableDb());
DaoSession daoSession = daoMaster.newSession();
想要操作User实体类,得先有一个UserDao:
userDao = daoSession.getUserDao();
3.添加数据:
User user = new User(null, "zhangsan" + random.nextInt(9999),"张三"); userDao.insert(user);4.删除数据:
ListuserList = (List ) userDao.queryBuilder().where(UserDao.Properties.Id.le(10)).build().list(); for (User user : userList) { userDao.delete(user); }
5.修改数据:
User user = userDao.queryBuilder() .where(UserDao.Properties.Id.ge(10), UserDao.Properties.Username.like("%90%")).build().unique(); if (user == null) { Toast.makeText(MainActivity.this, "用户不存在!", Toast.LENGTH_SHORT).show(); }else{ user.setUsername("王五"); userDao.update(user); }
6.查询数据:
ListOK,这就是greenDAO数据库框架的一个简单介绍list = userDao.queryBuilder() .where(UserDao.Properties.Id.between(2, 13)).limit(5).build().list(); for (int i = 0; i < list.size(); i++) { Log.d("google_lenve", "search: " + list.get(i).toString()); }