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Changes between Initial Version and Version 2 of Ticket #12870

-              initial
+              v2
 Here's a shell session which illustrates the problem.
+{{{
 >>> from tapped.deck.models import Deck
 >>> from django.db.models import Q
 …
 ('SELECT `deck_deck`.`id`, `deck_deck`.`format_id`, `deck_deck`.`name`, `deck_deck`.`slug`, `deck_deck`.`user_id`, `deck_deck`.`description`, `deck_deck`.`profile_cardinality`, `deck_deck`.`date_added`, `deck_deck`.`date_updated`, `deck_deck`.`date_refreshed`, `deck_deck`.`is_private`, `deck_deck`.`category`, `deck_deck`.`preconstructed_set_id`, `deck_deck`.`cost`, `deck_deck`.`view_count_cache`, `deck_deck`.`comment_count_cache`, `deck_deck`.`data_generated`, `deck_deck`.`image_token`, `deck_deck`.`similar_due`, `deck_deck`.`rating_votes`, `deck_deck`.`rating_score` FROM `deck_deck` INNER JOIN `auth_user` ON (`deck_deck`.`user_id` = `auth_user`.`id`) WHERE (`auth_user`.`username` = %s  AND NOT (`deck_deck`.`category` = %s  AND NOT (`deck_deck`.`category` IS NULL)) AND NOT (`deck_deck`.`category` = %s  AND NOT (`deck_deck`.`category` IS NULL)))', ('nammertime', 'pro', 'precon'))
+}}}