How to deal with storing user ids

[Manitary]

Some features, like reminders, require to store Discord user IDs in the database. Check whether it is feasible to deal with it in a way that is GDPR-compliant.

Is it enough to encrypt the db file and give the users a command to remove anything with their Discord user ID in the database? (and making sure that e.g. reminders are removed from the database upon expiration)