Database: superhero (difficulty: simple)
Question: Rank superheroes from DC Comics by their eye color popularity, starting with the most common color.
SQL: SELECT colour.colour AS EyeColor, COUNT(superhero.id) AS Count, RANK() OVER (ORDER BY COUNT(superhero.id) DESC) AS PopularityRank FROM superhero INNER JOIN colour ON superhero.eye_colour_id = colour.id INNER JOIN publisher ON superhero.publisher_id = publisher.id WHERE publisher.publisher_name = 'DC Comics' GROUP BY colour.colour