Android_GreenDao

一:greenDao是一个将对象映射到SQLite数据库中的轻量且快速的ORM解决方案

    GreenDao 3.0采用注解的方式来定义实体类，通过gradle插件生成相应的代码

二:依赖

Project里加入,不是项目里的而是工程里的gradle

buildscript {
    repositories {
        jcenter()
        mavenCentral()  ///////
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.3.3'
        classpath 'org.greenrobot:greendao-gradle-plugin:3.2.2' ////////
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

项目gradle

最上面添加:apply plugin: 'org.greenrobot.greendao'
dependencies下添加:compile 'org.greenrobot:greendao:3.2.2'
greendao{
    schemaVersion 1
    daoPackage 'com.greendao.gen'//自己的包名
    targetGenDir 'src/main/java'
}

添加完之后,Build  MakeProject构建一下,生成相应代码

三:使用

1:创建Person类,添加上注解之后Build  Make Module 'GreenDao' 生成相应代码

@Entity
public class Person {
    @Id
    private Long id;
    private String name;
    private int age;
    @Generated(hash = 1145075130)
    public Person(Long id, String name, int age) {
        this.id = id;
        this.name = name;
        this.age = age;
    }
    @Generated(hash = 1024547259)
    public Person() {
    }
    public Long getId() {
        return this.id;
    }
    public void setId(Long id) {
        this.id = id;
    }
    public String getName() {
        return this.name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return this.age;
    }
    public void setAge(int age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "Person{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}
2:创建类做数据库初始化工作
public class DbHelper {
    private static volatile DbHelper instance;
    private final DaoSession daoSession;

    private DbHelper(Context context) {
        //初始化数据库的配置
        DaoMaster.DevOpenHelper helper = new DaoMaster.DevOpenHelper(context,"user",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(Context context) {
        if (instance == null) {
            synchronized (DbHelper.class) {
                if (null == instance) {
                    instance = new DbHelper(context);
                }
            }
        }
        return  instance;
    }

    public PersonDao getPersonDao() {
        return daoSession.getPersonDao();
    }
}

3:使用增删改查
public class MainActivity extends AppCompatActivity {

    @BindView(R.id.btn_add)
    Button btnAdd;
    @BindView(R.id.btn_delete)
    Button btnDelete;
    @BindView(R.id.btn_update)
    Button btnUpdate;
    @BindView(R.id.btn_selete)
    Button btnSelete;
    private PersonDao dao;

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

        //拿到要操作的对象
        dao = DbHelper.getInstance(this).getPersonDao();
    }

    @OnClick({R.id.btn_add, R.id.btn_delete, R.id.btn_update, R.id.btn_selete})
    public void onViewClicked(View view) {
        switch (view.getId()) {
            case R.id.btn_add:
                Person person = new Person();
                person.setName("张三");
                person.setAge(23);
                dao.insert(person);
                break;
            case R.id.btn_delete:
                Person person1 = new Person();
                person1.setId(5L);
                dao.delete(person1);
                break;
            case R.id.btn_update:
                Person person2 = new Person(6L, "lisi", 24);
                dao.update(person2);
                break;
            case R.id.btn_selete:
                //List<Person> person3 = dao.queryRaw("where _id=? and name=?", "1","张三");//条件查询
                List<Person> person3 = dao.loadAll();//查询全部
                for(int i=0;i<person3.size();i++){
                    Log.i("TAG",person3.get(i).toString());
                }
                break;
        }
    }
}