Support for Transactions?

[anpr]

Is it possible to use transactions somehow?

[alejom99]

Any updates on this?

[kashifpk]

Transaction support in python-arango is experimental ATM.

http://python-driver-for-arangodb.readthedocs.io/en/master/transaction.html

The other issue is that only writes are supported by transactions atm.

That's one of the reasons I haven't started implementing it. Having transactions would be nice though. Suggestions on design and implementation are welcome.

Since arango requires specifying collections that will be written to in a transaction, the implementation has to tackle that too. The plan was to make the implementation similar to SQLAlchemy's transaction mechanism but that still requires some thinking.

[github-actions]

Stale issue message

[incorvia]

Is it worth revisiting this now? python-arango transactions

[kashifpk]

The limitation of only inserts being allowed in transactions is definitely gone. Python arango removed support for context managers so now transactions must be committed explicitly.

From arango-orm's perspective, implementing transactions as both a being/commit mechanism and a context manager makes more sense.

Usage style 1

from arango_orm import transaction

with transaction(Student, Teacher, Course) as txn:
    # do operations here

Usage style 2

from arango_orm  import transaction

txn = transaction(Student, Teacher, Course)
txn.begin()
# operations here
txn.commit()

Within the context manager, any (unhandled?) exceptions should cause the transaction to be rolled back.

It is worth exploring the potential API for this implementation.

[incorvia]

Sees Apache Age went with the the 'with' style format: https://github.com/apache/age/blob/master/drivers/python/samples/apache-age-note.ipynb

[SoundsSerious]

Would love to see this make it to production!

I prefer usage style II for low level operation capabilities, for deferred interaction as in an async system. But usage style I is really convenient but also somewhat trivial to implement with context managers.

A transaction class could have a context manager function that relies on style II syntax accomplishing both.

tx = ArangoTransaction(Tables,Graphs,ect)
with tx.context() as ctx:
    #add edges / docs

Are items added removed from the session like SQLAlchemy sessions?