Ignore Duplicates

[unboggling]

Starson, I hear you. That is interesting. Being a noob and not knowing that about ISBNs, I had made an assumption a few months ago that ISBNs might help. When I started using ISBNs more precisely, the incidents of losing title/author matches between library A and B seemed to become less frequent which seemed to support my wrong assumption about ISBNs. Taking ISBNs out of the equation, my problem has to be somehow related to title/author matches. I've always said yes to add dupes, and I've always (after trying it to see what the options did) kept automerge off, and in all cases the problem children were epub format, no other format existing in either library's matching titles' records.

[theducks]

Originally Posted by unboggling

Save to disk, opfs included. Add to different library using internal metadata not filename. If I remember correctly, it happened with exact author/title matches (I don't know why I said fuzzy before, sorry, that was a broadening assumption). But it happened often enough that it propelled me toward the precise isbn solution. That was months ago. Then a couple weeks ago it dropped an exact title/author/isbn/format match during save from libraryA then add to libraryB, automerge off, add dupes yes. I'll try to replicate it again and get back to you with exact documentation.

Edit. The 2 identicals with the isbn match were both in Library A, only one showed up in Library B.

You SHOULD NOT be using Save to Disk to add to ANY library

To add to a different Library: select books: Right-click: Copy To Library
Save to Disk is ONLY for someplace else (that is Not a Calibre Library).

[unboggling]

Wait. I shouldn't? Why not?

Maybe I wasn't clear before. I process a bunch of books in LibraryA. Now I want to move them to LibraryB. What I have been doing to accomplish that is save them out. Then I switch libraries to LibraryB. Then add them to LibraryB. The reason I was using Save/Add sequence rather than CopyToLibrary sequence was this: I thought I was certain that saving out would update all metadata changes into both opf and internal epub metadata. I thought I was NOT certain that CopyToLibrary would do that too, so for me it was a sort of habitual hygiene kind of thing.

Now I'm beginning to realize that it would be helpful to me to question every assumption I've ever made about how things work in calibre. I have a bad habit of making unwarranted assumptions then basing work and habits on them…. Sigh….

Edit: So, does CopyToLibrary update the opf and internal epub metadata in the copies of opf and epub that end up in the copied-to library?

2nd Edit: And if so, what's the difference if any in the end result, comparing those sequences (saveout/add vs copyto).

[kiwidude]

@unboggling - in relation to your other thread/post you made copy to library will prevent the need for you to worry about keeping some sort of placeholder file for your empty books. That sounds a fudge you do because of save to disc (which copy to library is a better alternative for in that case).

The opf file should always be up to date as I understand it, at worst there will be a small lag between the opf file being updated from when you update in Calibre as it writes using a background task. I do not believe the book itself will get updated with metadata using Copy to Library though - so if you absolutely insist on that being "done" prior to the book reaching your final library then what you are doing is valid. However for anyone who only reads the books on their devices, the actual send to device/save to disk you do from your final library will take care of that anyways. Your other alternative is to use the Modify ePub plugin if you want to the book to already have the latest metadata at the time.

I always use Copy to Library myself (or to be specific - the Copy with Delete after Copy option), way less steps and effort than Save to Disk (which you must save, then delete, then switch, then add). But Calibre does offer so many ways to do some things, there are pros and cons with each sometimes.

[unboggling]

Originally Posted by kiwidude

I do not believe the book itself will get updated with metadata using Copy to Library though - so if you absolutely insist on that being "done" prior to the book reaching your final library then what you are doing is valid. … But Calibre does offer so many ways to do some things, there are pros and cons with each sometimes.

@kiwidude, thank you for the multiple clarifications. They are helpful. Out of curiousity, why wouldn't I want to insist on the internal epub metadata being updated before it hits the final library? As I understand it, if I don't insist on it at that point, it may never EVER be updated unless I again save/send it out from there, in which case it would only be updated in the new saved/sended out copy, not in the copy remaining in my final/main library. Or did I misunderstand something else?

[theducks]

Originally Posted by unboggling

Wait. I shouldn't? Why not?

Maybe I wasn't clear before. I process a bunch of books in LibraryA. Now I want to move them to LibraryB. What I have been doing to accomplish that is save them out. Then I switch libraries to LibraryB. Then add them to LibraryB. The reason I was using Save/Add sequence rather than CopyToLibrary sequence was this: I thought I was certain that saving out would update all metadata changes into both opf and internal epub metadata. I thought I was NOT certain that CopyToLibrary would do that too, so for me it was a sort of habitual hygiene kind of thing.

That method is OK.
You were not inserting books into the other Library directly.

Copy to Library, will bring metadata for books that does not exist in the Library.
I believe there is a tweak that controls how much data gets written to the new Library.

[unboggling]

@Tony, sorry about hijacking your thread. That hijack started out sort of on topic and drifted off.

@theducks, it's temping to relate the jokes that arose in my mind. Heh. But I'll refrain. The tweak I saw there doesn't apply to my choice of preferred sequences to insure all metadata gets updated between the save and add operations. "Control how tags are applied when copying books to another library": "Set this to True to ensure that tags in 'Tags to add when adding a book' are added when copying books to another library". Now I'm trying to address the issue of exactly when the internal metadata in the actual book format gets updated.

Edit. Per kiwidude, CopyToLibrary doesn't do it.

Edit2. If I save/send an epub out then add to a different library, does the update of internal epub metadata happen during the save/send or during the add? Logically it must only happen during the Save to Disk or Send to devices, correct?

[theducks]

Originally Posted by unboggling

@Tony, sorry about hijacking your thread. That hijack started out sort of on topic and drifted off.

@theducks, it's temping to relate the jokes that arose in my mind. Heh. But I'll refrain. The tweak I saw there doesn't apply to my choice of preferred sequences to insure all metadata gets updated between the save and add operations. "Control how tags are applied when copying books to another library": "Set this to True to ensure that tags in 'Tags to add when adding a book' are added when copying books to another library". Now I'm trying to address the issue of exactly when the internal metadata in the actual book format gets updated.

Edit. Per kiwidude, CopyToLibrary doesn't do it.

Conversion and sending to device/Saving to Disk are the only times the BOOK file is modified. Nothing changed

[unboggling]

Originally Posted by theducks

Conversion and sending to device/Saving to Disk are the only times the BOOK file is modified. Nothing changed

And conversion. I forgot about that since I was thinking in terms of SaveToDisk/SendToDevice.

Edit: Thanks, all. I believe I'm relatively clear on that now.