notIn construction

[1ou]

I try get records from database like that:

    // Images
    fun getImage(watchedImages: List<Int>): Single<T> = (store select type)
            .where(Image::idImage.notIn(watchedImages))
            .orderBy(Random())
            .limit(1)
            .get()
            .observable()
            .firstOrError()

But in all cases i get some record from database. Even if i have 1 record in database which one has idImage equal 1, and watchedImages consists from [1]. In that case i wanna get error but i get in onSuccess instead of onError. Where am i making error?