将Android Room数据库与RXJava2一起使用时，找不到符号类EmptyResultSetException

Question

我正在尝试将RXJava2用于房间数据库。我使用单个可观察对象来获取我的对象列表。但每次我犯这个错误

找不到符号类EmptyResultSetException

我正在使用本教程ANDROID ROOM PERSISTENT和RXJAVA2

我以前在没有RXJava的AsyncTask中使用过它，它可以工作，所以我想在RXJava中使用它

这是我的身材。格拉德尔

apply plugin: 'com.android.application'

  android {
compileSdkVersion 28
defaultConfig {
    applicationId "apit.net.sa.simpleusingroom"
    minSdkVersion 16
    targetSdkVersion 28
    versionCode 1
    versionName "1.0"
    testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
    }
}
}

    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'




implementation 'com.android.support:support-v13:28.0.0'
implementation 'com.android.support:recyclerview-v7:28.0.0'
implementation 'com.android.support:design:28.0.0'
implementation 'com.jakewharton:butterknife:8.5.1'
    //ROOM database
implementation 'android.arch.persistence.room:runtime:1.0.0'
annotationProcessor 'android.arch.persistence.room:compiler:1.0.0'

//RXJava2
implementation 'io.reactivex.rxjava2:rxjava:2.1.9'
implementation 'io.reactivex.rxjava2:rxandroid:2.0.1'

//RXjava with room
implementation 'android.arch.persistence.room:rxjava2:1.0.0-alpha1'

annotationProcessor 'com.jakewharton:butterknife-compiler:8.5.1'
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'
 }

道类

 @Query("SELECT * FROM UserEntity")
Single<List<UserEntity>> getUsersSingle();

我的活动

DatabaseSingInstance.getInstance(this)
            .getOurDatabase()
            .userDAO()
            .getUsersSingle()
            .subscribeOn(Schedulers.io())
            .observeOn(AndroidSchedulers.mainThread())
            .subscribe(new DisposableSingleObserver<List<UserEntity>>() {


                @Override
                public void onSuccess(final List<UserEntity> userEntities) {
                    adapter = new UserAdapter(userEntities, MainActivity.this, new UserAdapter.OnLongClickListner() {
                        @Override
                        public void onClick(int position) {
                            showPopupWindow(userEntities,position);
                        }
                    });
                    myRec.setAdapter(adapter);
                }

                @Override
                public void onError(Throwable e) {
                    Log.e("error"," "+e.getMessage());
                }


            });

Answer 1

我根据这个答案解决了这个问题

我刚刚将room\u版本更改为1.1.0。顺便说一句，我正在等待任何一位能够解释这个错误或只是解释它发生的原因的人。