Suggestions on mechanism or existing code - maintain persistence of file download history

[Chris Angelico]

On Fri, Jan 31, 2020 at 7:56 PM R.Wieser <address at not.available> wrote:
>
> Dennis,
>
> > A full client/server RDBM should never be affected by an abort
> > of a client program.
>
> What you describe is on the single query level.   What I was thinking of was
> having several queries that /should/ work as a single unit, but could get
> interrupted (because of the OPs ctrl-c).
>
> Yes, Chris was probably right about using a transaction to fix that, but
> that has to be learned - knowledge I do not take for granted with a
> hobbyist.
>

Do you also permit people to drive cars without knowing about the
handbrake? When you start using a database, you have to learn how to
speak its language (usually SQL). Transactions are part of that. What
is so hard about this? They're not some esoteric thing that only a few
people use. EVERY request to a PostgreSQL database (and many other
DBMSes) is part of a transaction, whether implicit or explicit.

I Googled "postgres python tutorial". The first hit was
https://www.postgresqltutorial.com/postgresql-python/ and it mentions
transactions in the very first section, on connecting to the database.

Second hit: https://pynative.com/python-postgresql-tutorial/ - the
word "transaction" comes up on the landing page, albeit part way down;
but the first example that does any mutation does use an explicit
commit.

I didn't check for SQLAlchemy but it's likely the same.

Use transactions. Learn them.

ChrisA