[ownedbycats]

From chaley is this template which can be used to search for series with more than one book:

Originally Posted by chaley

This template search should be fast enough to use in a VL. You probably want to make it a stored template.

python:
def evaluate(book, context):
	# Return True ('yes') if the value in 'field' is used by more than 'test_count' books.
	# This template only works with single value fields such as Series, Publisher, and enumerations
	field = 'series'
	test_count = 1

	db = context.db.new_api
	id_map = context.globals.get('id_map')
	if id_map is None:
		context.globals['id_map'] = id_map = db.get_item_name_map(field)
		context.globals['item_book_count'] = db.get_usage_count_by_id(field)
	item_book_count = context.globals['item_book_count']

	item_id = id_map.get(book.get(field))
	if item_id is None or item_book_count.get(item_id, 0) <= test_count:
		return ''
	return 'yes'