ArticleDao.java

import androidx.lifecycle.LiveData;
import androidx.room.Dao;
import androidx.room.Insert;
import androidx.room.OnConflictStrategy;
import androidx.room.Query;

import java.util.List;

@Dao
interface ArticleDao {

    @Insert(onConflict = OnConflictStrategy.IGNORE)
    void addArticle(Article article);

    @Query("DELETE FROM articles")
    void deleteAll();

    @Query("SELECT * FROM articles")
    LiveData<List<Article>> getArticleList();

}