SQLite Forum

get changed columns data (previous/ after) on update row and previous data before delete row
I don't really know the C side of things, but according to [The pre-update hook page](https://www.sqlite.org/c3ref/preupdate_count.html), then once you're inside the registered callback you can use the sqlite3_preupdate_old() and sqlite3_preupdate_new() functions to get the old and new values of all the columns, and then decide what to do with them from there.