Found when fixing https://github.com/status-im/status-desktop/issues/16639
When a message is deleted, we need to delete the pins too as they are no longer available. This was done using an ON DELETE clause (thanks @osmaczko)
I also made sure the SELECT query for the pins doesn't return deleted messages
We only write up migrations, down migrations are not always possible in sqlite or
too complex/too expensive. For example to remove a column you would have to duplicate
the table, copy over the data, delete and recreated.
This can be very expensive for some tables (user_messages for example), so should not be attempted.
Notes
One issue we faced multiple times is that updates to user_messages can be very
expensive, leading to slow upgrade times and interrupted migrations. So avoid
writes if not necessary.
5a8310d5a7