SQLite:greenDAO

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
    }
}

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


greendao {
    schemaVersion 1 //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‘
}

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

    String name;
}

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;
    }
}