greendao的基本操作

Posted 2020-10-20 layfork

1.先配置项目的builder.gradle

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    
    repositories {
        google()
        jcenter()
    }
    dependencies {
        classpath ‘com.android.tools.build:gradle:3.0.0‘
        classpath ‘org.greenrobot:greendao-gradle-plugin:3.0.0‘
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        google()
        jcenter()
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

2.配置module.app的builder.gradle

apply plugin: ‘com.android.application‘
apply plugin: ‘org.greenrobot.greendao‘
android {
    compileSdkVersion 26
    defaultConfig {
        applicationId "com.lingdangmao.demo_zidingyi_textview"
        minSdkVersion 15
        targetSdkVersion 26
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile(‘proguard-android.txt‘), ‘proguard-rules.pro‘
        }
    }
}

dependencies {
    implementation fileTree(dir: ‘libs‘, include: [‘*.jar‘])
    implementation ‘com.android.support:appcompat-v7:26.1.0‘
    implementation ‘com.android.support.constraint:constraint-layout:1.0.2‘
    testImplementation ‘junit:junit:4.12‘
    androidTestImplementation ‘com.android.support.test:runner:1.0.1‘
    androidTestImplementation ‘com.android.support.test.espresso:espresso-core:3.0.1‘

    //greendao
    api ‘org.greenrobot:greendao:3.0.1‘
    api ‘org.greenrobot:greendao-generator:3.0.0‘
}
greendao {
    schemaVersion 1
    daoPackage ‘com.anye.greendao.gen‘
    targetGenDir ‘src/main/java‘
}

3.创建一个用户的实例类,创建完之后，编译一下，会自动生成文件

@Entity
public class User {
    @Id
    private Long id;
    private String name;
}

4.编写myapplication类继承application

public class MyApplication extends Application {
    private DaoMaster.DevOpenHelper mHelper;
    private SQLiteDatabase db;
    private DaoMaster mDaoMaster;
    private DaoSession mDaoSession;
    public static MyApplication instance;

    public static MyApplication getInstance(){
        return instance;
    }

    @Override
    public void onCreate() {
        super.onCreate();
        instance =this;
        setDataBase();
    }
    private void setDataBase(){
        mHelper = new DaoMaster.DevOpenHelper(this, "notes-db", null);
        db = mHelper.getWritableDatabase();
        // 注意：该数据库连接属于 DaoMaster，所以多个 Session 指的是相同的数据库连接。
        mDaoMaster = new DaoMaster(db);
        mDaoSession = mDaoMaster.newSession();

    }

    public DaoSession getmDaoSession() {
        return mDaoSession;
    }

    public SQLiteDatabase getDb() {
        return db;
    }
}

 

5.在activity中操作

//根据条件查询
        UserDao mUserdao = MyApplication.getInstance().getmDaoSession().getUserDao();
        Query<User> query =  mUserdao.queryBuilder().where(UserDao.Properties.Id.eq(21)).build();
        User u= query.unique();  //没有就是null
        Log.d(TAG, "onCreate11: "+u);
        Log.d(TAG, "onCreate11: "+u.getId());
        Log.d(TAG, "onCreate11: "+u.getName());


        //添加
        User mUser=new User((long)2,"mike");
        //mUserdao.insert(mUser);

        //删除
        //long id= 2;
        //mUserdao.deleteByKey(id);

        //改
        mUser = new User((long)2,"anye0803");
        mUserdao.update(mUser);

        //查询
        List<User> users = mUserdao.loadAll();
        for(int i=0;i<users.size();i++){
            Log.d(TAG, "onCreate: "+users.get(i).getId());
            Log.d(TAG, "onCreate: 1"+users.get(i).getName());
        }

完成，上面是最基本的，实际开发中用到再看