GreenDao 介紹：

greenDAO是一個(gè)對象關(guān)系映射（ORM）的框架，能夠提供一個(gè)接口通過操作對象的方式去操作關(guān)系型數(shù)據(jù)庫饼煞，它能夠讓你操作數(shù)據(jù)庫時(shí)更簡單浦旱、更方便。
官網(wǎng)地址：http://greenrobot.org/greendao/
github：https://github.com/greenrobot/greenDAO

GreenDao3.2使用方法

1.在項(xiàng)目的build.gradle添加如下配置

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.3.0'
        classpath  'org.greenrobot:greendao-gradle-plugin:3.2.1'//greendao
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

2.在app/build.gradle添加如下代碼

apply plugin: 'org.greenrobot.greendao'//greendao

 greendao {
        schemaVersion 1//數(shù)據(jù)庫schema版本號无畔，通過*OpenHelpers遷移數(shù)據(jù)，schema改變值增加吠冤。默認(rèn)為1
        daoPackage 'com.bupt.greeddaotest.dao'//生成DAOs浑彰、DaoMaster、DaoSession的包名拯辙。默認(rèn)為entities所在包名郭变。
        targetGenDir 'src/main/java'//生成DAOs、DaoMaster涯保、DaoSession的目錄诉濒。默認(rèn)為build/generated/source/greendao
 }

dependencies {
         compile 'org.greenrobot:greendao:3.2.0'
}

3.新建實(shí)體

@Entity
public class User {
    @Id(autoincrement = true)
    private Long id;
    @NotNull
    private String username;
    private int age;
    private String sex;
    private String address;
}

其中
@Entity 用于標(biāo)識這是一個(gè)需要Greendao幫我們生成代碼的bean
@Id 標(biāo)明主鍵，括號里可以指定是否自增
@NotNull 非空
此時(shí)編譯一下自動生成DaoMaster 夕春、DaoSession未荒、Dao，如圖所示 :

4.數(shù)據(jù)庫版本升級

數(shù)據(jù)庫版本升級使用了輔助庫GreenDaoUpgradeHelper
github：https://github.com/yuweiguocn/GreenDaoUpgradeHelper
1）在項(xiàng)目的build.gradle添加

allprojects {
    repositories {
        jcenter()
        maven { url "https://jitpack.io" }//使用數(shù)據(jù)庫升級輔助GreenDaoUpgradeHelper時(shí)添加
    }
}

2）在app/build.gradle添加

dependencies {
        // 使用數(shù)據(jù)庫升級輔助GreenDaoUpgradeHelper時(shí)添加
    compile 'com.github.yuweiguocn:GreenDaoUpgradeHelper:v1.3.0'
}

3）新建如下類

public class MySQLiteOpenHelper extends DaoMaster.OpenHelper {
    public MySQLiteOpenHelper(Context context, String name, SQLiteDatabase.CursorFactory factory) {
        super(context, name, factory);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        super.onUpgrade(db, oldVersion, newVersion);
        MigrationHelper.migrate(db,UserDao.class);//版本升級
    }
}

一個(gè)簡單的實(shí)例

1）在自定義application里面設(shè)置數(shù)據(jù)庫

public class MeApplication extends Application {

    private static MeApplication application;
    private MySQLiteOpenHelper openHelper;
    private Database db;
    private DaoMaster daoMaster;
    private DaoSession daoSession;
    public static String database_name = "record-db";


    @Override
    public void onCreate() {
        super.onCreate();
        application = this;
        setDatabase();
    }

    private void setDatabase() {
        openHelper = new MySQLiteOpenHelper(this, database_name, null);
        db = openHelper.getWritableDatabase();//獲取可寫數(shù)據(jù)庫
        daoMaster = new DaoMaster(db);
        daoSession = daoMaster.newSession();
    }

    public static MeApplication getMeApplication(){
        return application;
    }

    public DaoSession getDaoSession() {
        return daoSession;
    }


    public Database getDb() {
        return db;
    }
}

2）插入數(shù)據(jù)

/**
     * 插入一條記錄
     *
     */
    public void insertUser(UserDao userDao,User user) {;
        userDao.insert(user);
    }

    /**
     * 插入用戶集合
     *
     */
    public void insertUsers(UserDao userDao,List<User> users) {
        if (users == null || users.isEmpty()) {
            return;
        }
        userDao.insertInTx(users);
    }

3）刪除數(shù)據(jù)

/**
     * 刪除一條記錄
     *
     */
    public void deleteUser(UserDao userDao,User user) {
        userDao.delete(user);
    }

/**
     * 刪除用戶集合
     *
     */
    public void deleteUsers(UserDao userDao,List<User> users) {
        if (users == null || users.isEmpty()) {
            return;
        }
        userDao.deleteInTx(users);
    }

4）更新數(shù)據(jù)

/**
     * 更新一條記錄
     *
     */
    public void updateUser(UserDao userDao,User user) {
        userDao.update(user);
    }
/**
     * 更新用戶集合
     *
     */
    public void updateUsers(UserDao userDao,List<User> users) {
        if (users == null || users.isEmpty()) {
            return;
        }
        userDao.updateInTx(users);
    }

5）查詢數(shù)據(jù)

/**
     * 查詢用戶列表
     */
    public List<User> queryUsers(UserDao userDao) {
        List<User> list = userDao.queryBuilder().list();
        return list;
    }
/**
     * 查詢用戶列表
     */
    public List<User> queryUsers(UserDao userDao,int age) {
        //按照年齡從小到大排列
        List<User> list = userDao.queryBuilder().where(UserDao.Properties.Age.gt(age)).orderAsc(UserDao.Properties.Age).list();
        return list;
    }