Re: Re: psycopg3 transactions - Mailing list psycopg

From Daniel Fortunov
Subject Re: Re: psycopg3 transactions
Date
Msg-id CAH1rg6av5MR+yhEpwaxZNH+QrW+9ya9BQTx+w_Q9crm3e65yZQ@mail.gmail.com
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In response to Aw: Re: psycopg3 transactions  (Karsten Hilbert <Karsten.Hilbert@gmx.net>)
Responses Re: Re: psycopg3 transactions
List psycopg
On Thu, 14 Oct 2021, 11:05 Karsten Hilbert, <Karsten.Hilbert@gmx.net> wrote:
>My conclusion is that the only sane thing to do is:
>1. Only ever create connections in autocommit mode.
>2. Only ever use `with connection.transaction()` to control transactions.
>3. Forget that `connection.commit()` and `connection.rollback()` exist, and never use them.

What if you need to rollback a hitherto valid transaction ?

Transactions are there for a reason. It seems best to explicitely use them ?

I'm not sure I fully understand your question/statement but let me try to respond.

We are still "using transactions", just with more precise, more explicit*, and more flexible* semantics, represented by a context manager.

Rolling back a transaction is possible by raising a Rollback exception within a block.

I hope this answers your question but if not please describe the scenario you are thinking about.

Dani

(*More explicit because in the conventional autocommit=false approach, the beginning of the transaction is an implicit side-effect of executing another statement, which may or may not actually begin a transaction depending on whether one is in progress. More flexible because you can have nested transaction blocks which operate in an independent and composable way.)


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