Not lock runtime python

[leandrogmuller]

I need to execute merge, but not lock object during the process.

engine = create_engine("postgresql://user:pass@localhost:5432/datadev",poolclass=NullPool)

for i in range(3):
session_factory = sessionmaker(bind=engine)
session = session_factory()
lang03 = session.query(Lang03).filter(Lang03.pkge == 'kernel').first()
lang03.text = 'aa'
session.merge(lang03) #second attempt lock the code running. I dont't want lock the runtime.

[CaselIT]

Hi,

I'm not sure why you would want to merge an object that's already in the session. See the documentation for details https://docs.sqlalchemy.org/en/14/orm/session_api.html?highlight=merge#sqlalchemy.orm.Session.expunge

[zzzeek]

well also it shouldn't "lock" anything, what kind of "lock" are we referring towards? a database lock or some kind of threading mutex is invovled somewhere?

[leandrogmuller]

Hi.
I saw lock on database. The session is locking database record before commit.

[zzzeek]

SQLAlchemy just emits the SQL you give it. the psycopg2 driver will emit BEGIN TRANSACTION ahead of that. turn on Postgresql SQL logging and you'll be able to see all commands being received by the database.