Virtual Library - Finding authors with only one book

[Georgie W]

From my Calibre Total Library, I have created a smaller virtual library ("My Kindle") which shows all the books actually loaded on my kindle (yes, OK, obv!) - about 3,000 books. In Calibre, I have created collections for each author (with some individual tweaks) and I use the Kindle Collections add-in to replicate these on my kindle.

What I want to do is to search on Calibre for where an author has only one book in the virtual library. E.g. there are 20 books in my Total Library "Agatha Christie" collection, but only one of them is in My Kindle virtual library. So on my kindle, I'm displaying a collection ("Agatha Christie") with only one book in it.

I have looked at the ABC add-in, which will give me the number of books by each author, but only as relates to my Total Library. It can't be tweaked to report just on my virtual library.

Grateful for any suggestions.

[ownedbycats]

In 5.x, this would be difficult, though you can sort categories by 'number of books' in the tag browser.

Running Calibre from source (currently it's on the 6 beta) added a template function that may help. See these for more info:
https://www.mobileread.com/forums/sh...d.php?t=347693
https://www.mobileread.com/forums/sh...5&postcount=83

[Georgie W]

Thanks - the second template example looks interesting, and I'll wait for 6.x to be available.

[chaley]

The functions are in calibre 5.99.12 (the calibre 6 beta).

This stored template and template search do the job, assuming I understand you correctly.

Stored template: authors_only_one_book

program:
	vals = globals(vals='');
	if !vals then
		all_authors = book_values('authors', 'authors:true', '&', 1);
		for aut in all_authors separator '&':
			if book_count('authors:="' & aut & '"', 1) == 1 then 
				vals = list_join('&', vals, '&', aut, '&')
			fi
		rof;
		set_globals(vals)
	fi;

	res = '';
	for aut in 'authors':
		if str_in_list(vals, '&', aut, 1, '') then
			res =  1;
			break
		fi
	rof;
	return res

The template search:

template:"program: authors_only_one_book()#@#:n:1"