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greendao的基本操作讲解

xmjava 2021年02月16日 手机开发 229 0

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); 
 
        // 
        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

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