Anki Forums

Custom study not working?

I’ve tried having a custom study session using pre-made decks. I input the maximum number of cards to the maximum (99999). After I select the tags, a window popped up:

Error
An error occurred. Please use Tools > Check Database to see if that fixes the problem.
If problems persist, please report the problem on our support site. Please copy and paste the information below into your report.
Anki 2.1.38 (355e4cd5) Python 3.8.6 Qt 5.14.2 PyQt 5.14.2
Platform: Windows 10
Flags: frz=True ao=False sv=2
Add-ons, last update check: 2021-02-18 14:08:23

Caught exception:
Traceback (most recent call last):
File “aqt\customstudy.py”, line 193, in accept
File “anki\schedv2.py”, line 1068, in rebuild_filtered_deck
File “anki\rsbackend_gen.py”, line 171, in rebuild_filtered_deck
File “anki\rsbackend.py”, line 256, in _run_command
anki.rsbackend.DBError: DBError { info: “SqliteFailure(Error { code: Unknown, extended_code: 1 }, Some(“Expression tree is too large (maximum depth 1000)”))”, kind: Other }

Does anyone know how to fix this? thanks!

Seems you’re using a really big query that’s exceeding a maximum limit. I don’t know of a way to bypass the limit (It’s not something set by Anki, but by sqlite, though it can be changed).

How many tags did you select?

1 Like

Approximately how many tags are you selecting?

I used AnKing decks, which has been notoriously known to be the lifesaver for medical students for its vast array of decks and tags. I didn’t count approximately how many tags I exclude, but what I know for sure is that I include 5 tags and exclude the rest (lots and lots of them). Is it wrong to do so?

Do you mean that you only include the tags you need and then also exclude tags you don’t need? Or just add the tags you need which is what you need? Could you post your search string?

1 Like

You don’t need to explicitly exclude tags you’re not interested in, unless they overlap with the tags you are interested in. Have you tried just listing the tags you’re interested in and leaving the exclude section unselected?