Every book in my database now appears twice!

[couponprof]

I've been off Calibre for a while but logged in earlier this week and found that suddenly every item in my library appears twice! I have thousands of entries in here, so deleting every other entry manually is not really feasible.

I looked in the My Calibre Library folder on my hard drive and everything only seems to be there once so I'm not sure what's going on.

I tried to create a new library by creating an empty library in a new folder - it said that the library database at that new location (an empty folder) appears to be corrupted.

I am on an Windows desktop and currently have calibre 7.4 installed.

Can anyone help me with this? I'm really getting frustrated. Should I delete Calibre completely and reinstall it?

[Karellen]

Before doing anything drastic like deleting Calibre, run a diagnostic Check Library first. Right click on the "ebooks" library icon...

[couponprof]

I tried that - although for me it was in the "Calibre Library" icon. It said "Found no errors in your calibre library database"

It also asked if I wanted it to check if the files in my library match the info in the database so I said yes. It said they did match.

What should I do now?

[couponprof]

I also updated Calibre to the new version - Calibre 7.21 - and now there are THREE copies of each book!

[slm]

Are there actually three folders for each book in the Calibre folder on your drive?

[Sirtel]

And can you post a screenshot about those triple entries? You can do that by going Advanced and clicking on the paperclip icon, to add an attachment.

[couponprof]

It does not look like the actual files are duplicated on my hard drive - I looked in the My Calibre Library folder and only see one copy of each book.

I've (hopefully!) attached a screenshot that shows how the books are duplicated in Calibre.

[JSWolf]

Originally Posted by couponprof

It does not look like the actual files are duplicated on my hard drive - I looked in the My Calibre Library folder and only see one copy of each book.

I've (hopefully!) attached a screenshot that shows how the books are duplicated in Calibre.

What happens if you delete one of the duplicates?

[Karellen]

Over in the right pane below the cover image, there should be an item named "Book files"
If you click on it for each of the three entries, does it open the same folder?

[couponprof]

Okay, this is interesting. Apparently my library is not located in the "My Calibre Library" file as I thought. When I click on the book files links for the 3 copies of a single book, it takes me to a different folder, "Calibre Library", which is not in the main e-book folder of my hard drive. In that folder, Calibre Library, there are three different folders for each book. They each have the same title but then have a different number in parentheses after the title.

So for the book Clobbered by Camembert (a cute cozy mystery, lol) there are three folders - one is Clobbered by Camembert (7), the others have (8190) and (10293) after them. No clue what these numbers stand for - while this book is in a series, it's #3, not #7. When I look in these three folders, the contents are mostly identifical but only the first one (7) containes a metadata file. My guess is that this is the original and the others are the duplicates.

I looked in some of the other folders of authors and noticed that some have only two copies of a books and there are a few without duplicated entries.

I also see that the numer of folders in Calibre Library (1941) is larger than the number of folders in My Calibre Library (1600). Each folder is an author, so there are multiple books in some of these (not counting duplicates).

FYI, I'm heading off on a work trip tomorrow so won't have access to Calibre for a few days.

I tried deleting two copies of the first book in this series and there is now only one folder, with the number (5) at the end and the metadata file included.

[ownedbycats]

The number is the Calibre ID - it's how Calibre's database identifies a specific book, since title and author can change (or be the same as another book).

It sounds halfway like your library folder got re-added to itself but I can't think of any way to invoke that without noticing.

Is this Calibre library on any sort of NAS or cloud storage such as Dropbox or OneDrive? You're not supposed to do that, and we get at least a post a week from people who've messed up their libraries by doing so.

[couponprof]

It is actually on my hard drive. It is backed up on Carbonite as well.

Am I going to have to go through and delete the duplicates individually? Shame I can't sort by the numbers instead of the titles - then I could just delete all the large numbered folders.

If I do have to do a manual delete, is is better to delete the folders from my hard drive or the entries from Calibre?

[ownedbycats]

The entries from Calibre. You shouldn't mess around in your library folder at all.

[Karellen]

And you might want to disable, or set to zero, the caltrash bin, otherwise every book you delete will end up cached for a period of time. (in case you change your mind and really wanted to keep the book.)

Right-click on the "Remove Books" icon, and select "Restore recently deleted" and set "Permantly Delete after" to zero.

All those duplicate folders, were they all added into Calibre on the same day? or maybe a small range of dates? (In the edit metadata screen check "Date:")
If they were you could do a search like date:=2024-02-07 for 7 Feb 2024, then simply delete all the listed items.

[Comfy.n]

The Find Duplicates plugin may be useful, I guess. It can find duplicates across multiple libraries, producing a report.

(first thing I would do in such a case would be to rename the libraries to more distinctive names, to avoid further confusion)