### Database Schema:
CREATE TABLE user_reviews (
	App	TEXT	NULL,
	Translated_Review	TEXT	NULL,
	Sentiment	TEXT	NULL,
	Sentiment_Polarity	TEXT	NULL,
	Sentiment_Subjectivity	TEXT	NULL,
	foreign key (App) references playstore (App)
);

CREATE TABLE playstore (
	App	TEXT	NULL,
	Category	TEXT	NULL,
	Rating	REAL	NULL,
	Reviews	INTEGER	NULL,
	Size	TEXT	NULL,
	Installs	TEXT	NULL,
	Type	TEXT	NULL,
	Price	TEXT	NULL,
	`Content Rating`	TEXT	NULL,
	Genres	TEXT	NULL
);

### User's Query:
Which apps have not been updated since year 2015 and what kind of sentiment users hold on it?

### Extra Knowledge:
since year 2015 refers to "Last Updated"<'January 1, 2015';
SELECT DISTINCT App, Sentiment FROM user_reviews WHERE App IN ( SELECT App FROM playstore WHERE CAST(SUBSTR('Last Updated', -4, 4) AS INTEGER) < 2015 )