On Thu, Apr 1, 2021, at 11:20 AM, Soumaya Mauthoor wrote: > Hello Mike > > Thanks for quick response! I don't have postgres installed right now so I > tried with sqlite, which is also autocommit by default. Example
ahha - that's again a very specific quirk of the pysqlite driver that it does not autobegin the transaction if DDL is encountered, which is a bug in the driver, see https://bugs.python.org/issue9924 This autocommit situation has been mostly unchanged since I first started SQLAlchemy in 2005. So I've been working with this behavior literally every day for sixteen years with a dozen or more DBAPI drivers. It's safe to trust I know what i am speaking of ! :) > > > > > : > > >>> from sqlalchemy import text, create_engine > >>> e = create_engine('sqlite:///foo.db') > >>> with e.connect() as conn: conn.execute(text('create table test(int > >>> col1)')) > ... > <sqlalchemy.engine.cursor.LegacyCursorResult object at 0x7f6257fba7c0> > >>> e.execute('select * from test').fetchall() > [] > > I didn't commit the transaction, but it seems to have autocommited since I > can query it in the following query? > > Soumaya > > Le jeu. 1 avr. 2021 à 15:27, Mike Bayer <mike...@zzzcomputing.com> a écrit : >> __ >> >> >> On Thu, Apr 1, 2021, at 10:06 AM, sumau wrote: >>> Hello >>> >>> Following advice from this article: >>> https://www.oddbird.net/2014/06/14/sqlalchemy-postgres-autocommit/ >>> >>> and because we run large, consecutive queries, we set our transaction >>> isolation level to 'autocommit' when connecting to our postgres DB. This >>> means we cannot create explicit transactions and use begin() and commit(): >>> https://www.oddbird.net/2014/06/14/sqlalchemy-postgres-autocommit/ >>> >>> This has not a problem so far because we can create another (temporary) >>> connection when we do want to have a roll-backable transaction. However >>> since postgres DB is set to autocommit by default, I was wondering whether >>> setting the transaction isolation level to 'autocommit' was needlessly >>> complicated? >> >> the Python DBAPI is transactional by default and the "autocommit" feature of >> many DBAPIs is not part of the specification: >> https://www.python.org/dev/peps/pep-0249/ . the psycopg2 driver, as well >> as all other DBAPI drivers, are not in autocommit by default. >> >> >> >> >> >>> >>> For example in the example explained here: the >>> https://docs.sqlalchemy.org/en/14/tutorial/dbapi_transactions.html#getting-a-connection >>> the query will still be committed, even if don't explicitly commit the >>> transaction or the transaction isolation level to 'autocommit'. >> >> respectfully, that is incorrect for the DBAPI drivers included in >> SQLAlchemy, provided you aren't using MySQL with MyISAM tables. try it out >> >> >> >> >>> >>> Regards >>> Soumaya >>> >>> -- >>> SQLAlchemy - >>> The Python SQL Toolkit and Object Relational Mapper >>> >>> http://www.sqlalchemy.org/ >>> >>> To post example code, please provide an MCVE: Minimal, Complete, and >>> Verifiable Example. See http://stackoverflow.com/help/mcve for a full >>> description. >>> --- >>> You received this message because you are subscribed to the Google Groups >>> "sqlalchemy" group. >>> To unsubscribe from this group and stop receiving emails from it, send an >>> email to sqlalchemy+unsubscr...@googlegroups.com. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/sqlalchemy/5d474102-1212-4e8e-b26e-a78815ed5829n%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/sqlalchemy/5d474102-1212-4e8e-b26e-a78815ed5829n%40googlegroups.com?utm_medium=email&utm_source=footer>. >> >> >> -- >> SQLAlchemy - >> The Python SQL Toolkit and Object Relational Mapper >> >> http://www.sqlalchemy.org/ >> >> To post example code, please provide an MCVE: Minimal, Complete, and >> Verifiable Example. See http://stackoverflow.com/help/mcve for a full >> description. >> --- >> You received this message because you are subscribed to the Google Groups >> "sqlalchemy" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to sqlalchemy+unsubscr...@googlegroups.com. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/sqlalchemy/4cbda2cc-09ef-4a5c-be20-3bc710898fe0%40www.fastmail.com >> >> <https://groups.google.com/d/msgid/sqlalchemy/4cbda2cc-09ef-4a5c-be20-3bc710898fe0%40www.fastmail.com?utm_medium=email&utm_source=footer>. > > -- > SQLAlchemy - > The Python SQL Toolkit and Object Relational Mapper > > http://www.sqlalchemy.org/ > > To post example code, please provide an MCVE: Minimal, Complete, and > Verifiable Example. See http://stackoverflow.com/help/mcve for a full > description. > --- > You received this message because you are subscribed to the Google Groups > "sqlalchemy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sqlalchemy+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/sqlalchemy/CAN14jWQsMN66PBeh0Vg7xu4UPHecMqZut-bGccwdAvLLoZCHNQ%40mail.gmail.com > > <https://groups.google.com/d/msgid/sqlalchemy/CAN14jWQsMN66PBeh0Vg7xu4UPHecMqZut-bGccwdAvLLoZCHNQ%40mail.gmail.com?utm_medium=email&utm_source=footer>. -- SQLAlchemy - The Python SQL Toolkit and Object Relational Mapper http://www.sqlalchemy.org/ To post example code, please provide an MCVE: Minimal, Complete, and Verifiable Example. See http://stackoverflow.com/help/mcve for a full description. --- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. 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