Offline downloads fail with SQLITE_CONSTRAINT_FOREIGNKEY for users with restricted library access

[CoSciBlog]

Description

Komelia V0.19.0

Komga V1.26.3

Offline downloads in Komelia fail for Komga users that have restricted permissions and do not have access to all libraries.

I have multiple users configured on my Komga server.

When I log into Komelia with my administrator account, downloading books/chapters for offline use appears to work normally.

I also tried to empty the cache and reinstalled the app on my tablet.

However, when I log in with a regular non-admin user that only has access to selected libraries, offline downloads fail with the following SQLite error:

org.sqlite.SQLiteException: [SQLITE_CONSTRAINT_FOREIGNKEY]
A foreign key constraint failed (FOREIGN KEY constraint failed)

[Snd-R]

Can't reproduce. This issue should've been fixed in 0.18.6.
How did you install the app? apk, playstore or fdroid?

[CoSciBlog]

Can't reproduce. This issue should've been fixed in 0.18.6. How did you install the app? apk, playstore or fdroid?

I used the apk from github, i also have the same problem on my phone, same source

[Snd-R]

https://github.com/Snd-R/Komelia/releases/tag/0.20.0 Should have a more detailed error with sql included
Can you try and get exact SQL here?

[CoSciBlog]

https://github.com/Snd-R/Komelia/releases/tag/0.20.0 Should have a more detailed error with sql included Can you try and get exact SQL here?

Now i get this one

Book downloaded error 0045 - Chapter 00044 - The 8th son, Are you kidding me org.jetbrains.exposed.v1.exceptions.ExposedSQLException: org.sqlite.SQLiteException: [SQLITE_CONSTRAINT_FOREIGNKEY] A foreign key constraint failed (FOREIGN KEY constraint failed) SQL: [INSERT INTO USER_LIBRARY_SHARING (user_id, library_id) VALUES (?, ?), INSERT INTO USER_LIBRARY_SHARING (user_id, library_id) VALUES (?, ?), INSERT INTO USER_LIBRARY_SHARING (user_id, library_id) VALUES (?, ?), INSERT INTO USER_LIBRARY_SHARING (user_id, library_id) VALUES (?, ?), INSERT INTO USER_LIBRARY_SHARING (user_id, library_id) VALUES (?, ?), INSERT INTO USER_LIBRARY_SHARING (user_id, library_id) VALUES (?, ?), INSERT INTO USER_LIBRARY_SHARING (user_id, library_id) VALUES (?, ?), INSERT INTO USER_LIBRARY_SHARING (user_id, library_id) VALUES (?, ?), INSERT INTO USER_LIBRARY_SHARING (user_id, library_id) VALUES (?, ?), INSERT INTO USER_LIBRARY_SHARING (user_id, library_id) VALUES (?, ?), INSERT INTO USER_LIBRARY_SHARING (user_id, library_id) VALUES (?, ?), INSERT INTO USER_LIBRARY_SHARING (user_id, library_id) VALUES (?, ?), INSERT INTO USER_LIBRARY_SHARING (user_id, library_id) VALUES (?, ?), INSERT INTO USER_LIBRARY_SHARING (user_id, library_id) VALUES (?, ?), INSERT INTO USER_LIBRARY_SHARING (user_id, library_id) VALUES (?, ?)] 2026-09-27 13:21 Book downloaded error 0020 - Chapter 00020 - The 8th son, Are you kidding me ExposedSQLException: org.sqlite.SQLiteException: [SQLITE_CONSTRAINT_FOREIGNKEY] A foreign key constraint failed (FOREIGN KEY constraint failed) 2026-09-23 03:27

[Snd-R]

I see the issue. The other restricted libraries are not getting imported.
I think it doesn't make sense to restrict offline user libraries so I'll remove this part entirely
Will be fixed in the next release

[CoSciBlog]

How exactly does the offline Mode work in the app? Do i have to go offline/disable wifi or does it also use the offline versions when i am on wifi/mobile data and automatically use the local files instead of the online versions?

[Snd-R]

You have to manually switch to offline mode and back
If you fail to login when launching the app, you will be suggested to use offline mode as well
Right now it always uses online version of files while online

[CoSciBlog]

You have to manually switch to offline mode and back If you fail to login when launching the app, you will be suggested to use offline mode as well Right now it always uses online version of files while online

ah ok thanks, i hoped it would automatically switch or prefer already downloaded books, that's a feature i'm missing on other apps like jellyfin too where i often use my tablet on mobile data or slow hotspots and could preload them at home with wifi and then automatically use/first use the local cached/downloaded version or to speed up the change between books(maybe that could also be a future feature that the next book starts preloading 2 or 3 pages before the current one is finished)