Searching in binary field

[Manichean]

I just ran into a problem trying to use a custom binary column for distinguishing between my study textbooks and, well, every other ebook. My plan was to use the column to indicate whether a specific book is a textbook (=true) or not (=false), and then build a saved search to restrict library view to only textbooks or only every other kind of book. But while building the search pattern I ran into the problem: I've found that searching for col:true returns all books with a set value, be it true or false, while col:false returns every undefined book. But searching for actual values doesn't work: Every time I try to search for col:yes, col:no or any variation I could think of I'd get an empty search result (and yes, there are some books with each value set). So, my question is: How do you actually search for books with a specific value in a binary metadata field?

[kovidgoyal]

Yes and no are the correct way, I just tried it, works for me. Are you sure you're not forgetting the leading #?

[Manichean]

Originally Posted by kovidgoyal

Yes and no are the correct way, I just tried it, works for me. Are you sure you're not forgetting the leading #?

Well, I was being kind of stupid, I think. I just found out why it didn't work: I'm using the german version of Calibre, and for some reason I have to use "Ja/Nein" as search queries as opposed to yes/no, which I personally find to be a bit counterintuitive, by the way (So, the actual queries I'm using now are "#fach:Ja" and "#fach:Nein", obviously without the quotes.)

Thanks anyway for your help.

EDIT: Actually, this goes to show that I can't think of enough variations on a search pattern to get it to work