Hello greenDAO（SQLite）

一、配置Gradle Scripts：

1.1、build.gradle(Project:*****)

buildscript {
    repositories {
        google()
        jcenter()
        mavenCentral() // add repository
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.2.1'//3.3.2 会告警
        classpath 'org.greenrobot:greendao-gradle-plugin:3.2.2' // add plugin
    }
}

1.2、build.gradle(Module:app)

apply plugin: 'com.android.application'
apply plugin: 'org.greenrobot.greendao' // apply plugin

greendao {
    schemaVersion  //数据库版本号
    daoPackage 'com.trysqlite.greenDAO'    // 设置包名（这里自己定义一下你的命名空间位置）
    targetGenDir 'src/main/java'           //设置 生成代码位置
    generateTests false                    //设置为true以自动生成单元测试。
//  targetGenDirTests 'src/main/java'      //应存储生成的单元测试的基本目录。默认为 src / androidTest / java。
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'

    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'

    implementation 'org.greenrobot:greendao:3.2.2' 
    implementation 'org.greenrobot:greendao-generator:3.0.0'
}

二、创建存储对象类（记住要@Entity，这样才会被构建相对应的操作类）：

@Entity
public class teacher {
    @Id(autoincrement = true)
    Long id;

　　@Property(nameInDb = "name") //设置了，数据库中的表格属性名为"name",如果不设置，数据库中表格属性名为"NAME"
　　private String name;

}

三、菜单栏选择Build->Make Project

这里将生成：

• DaoMaster：使用GreenDAO的入口点
• DaoSession：管理特定架构的所有可用DAO对象：说白了就是增删查改数据库操作
• teacherDao：数据访问对象(第二部写的实体类)

四、新建一个继承Application的类，对GreenDao进行初始化

public class MyApplication extends Application {
     private static DaoSession daoSession;

    @Override
    public void onCreate() {
        super.onCreate(); //进入程序时初始化数据库
        settupDatabase();
    }
     private void settupDatabase() {
        //创建数据库
        DaoMaster.DevOpenHelper helper = new DaoMaster.DevOpenHelper(this, "its_android.db", null);
        //获取可写数据库
        SQLiteDatabase db = helper.getWritableDatabase();
        //获取数据库对象
        DaoMaster daoMaster = new DaoMaster(db);
        //获取Dao对象管理者
        daoSession = daoMaster.newSession();
    }

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

五、做个预处理好的DBHelper

public class DBHelper {
    static DaoSession daoSession = app.getDaoInstant();

    //增
    public void Addteacher(teacher teacher) {
        daoSession.getTeacherDao().insert(teacher);
    }

    //删
    public void Deleteteacher(teacher teacher) {
        daoSession.getTeacherDao().delete(teacher);
    }

    //查
    public List<teacher> Queryteacher(teacher teacher) {
        QueryBuilder<teacher> qb = daoSession.queryBuilder(teacher.class);
        QueryBuilder<teacher> teacherQueryBuilder = qb.where(teacherDao.Properties.Name.eq("一")).orderAsc(teacherDao.Properties.Name);
        List<teacher> teacherList = teacherQueryBuilder.list(); //查出当前对应的数据
        return teacherList;
    }

    //改
    public void Updateteacher(teacher teacher) {
        daoSession.getTeacherDao().update(teacher);
    }

}