Delete unnecessary media duplicates created by WPML (with EN as source language)

clean-wpml-media-duplicates.sql

DELETE FROM
	wp_posts
WHERE
	post_type = 'attachment'
	AND ID NOT IN(
		SELECT
			MIN(ID)
			FROM (
				SELECT
					ID, post_type, post_name FROM wp_posts) AS r1
				JOIN wp_icl_translations ON (ID = element_id)
			WHERE
				post_type = 'attachment'
				AND language_code = 'en'
			GROUP BY
				post_name
  )
	AND ID IN(
		SELECT
			ID FROM (
				SELECT
					ID, post_type FROM wp_posts) AS r2
				JOIN wp_icl_translations ON (ID = element_id)
			WHERE
				post_type = 'attachment'
				AND language_code = 'en'
  );

I used this to clean up my messed-up WordPress database, where WPML created several duplicates for the same images in the database.
Make sure to change 'en' to your source language and always back up your database before using commands like this.