During the session user can make multiple actions with db access

Instead of storing all values I would prefer to keep a instance of the class

Can this be done? or I'd need to get the object to update ?

I'm currently migrating from django orm, in django I can store a orm object and call save() whenever I want to commit changes I made

In Pony all modified objects are saved automatically at the end of db_session. The benefit of this is that it is not necessary to manually track which objects should be saved The drawback is that you don't have manual control of which updated objects to save (usually it is not necessary, and all modified objects should be saved) Currently Pony doesn't allow to "disconnect" object from db_session. So you probably need to store modified data inside a dict, and at the end of user session find user object by id and update its fields

I see

Is there a function to get all data from an object? and also one for setting it?

for getting data you can use obj.to_dict() https://docs.ponyorm.org/api_reference.html#Entity.to_dict for setting you can do: for key, value in d.items(): setattr(obj, key, value)

Great, thanks!

class ORMWrapper: def __init__(self, obj): self.__dict__ = obj.to_dict() self.ORMClass = type(obj) def save(self): with db_session: obj = self.ORMClass.get(id=self.id) for key, value in self.__dict__.items(): if key == 'ORMClass': continue setattr(obj, key, value) def delete(self): with db_session: obj = self.ORMClass.get(id=self.id) obj.delete()

Just made that to make my life easier ^^

Is select(p for p in Product if p.price > 100) faster than Product.select(lambda p: p.price>100) ?

Is select(p for p in Product if p.price > 100) faster than Product.select(lambda p: p.price>100) ?

It is the same

hi, i'm trying to do something like: select((p.name, p.price) for p in Product).sort_by(lambda p: p.factory) but i get: TypeError: Incorrect number of lambda arguments. Expected: 2, got: 1

why? 🤔

You select (p.name, p.price) this is a tuple of two elements. They will be used in lambda function

so how can i get 2 elemets from class Product ?

select((cc.content, cc.content_type) for cc in CommandContent if cc.command.name == name).sort_by(lambda cc: cc.order)

so how can i get 2 elemets from class Product ?

select the whole “p” row and then use “p.name” etc in your code after the query

select the whole “p” row and then use “p.name” etc in your code after the query

thank you! 😁👍

hello people Let me ask for some references ----> I was searching conparatives until found this presentation in 2015 https://es.slideshare.net/jmoc25/python-comparing-orm-55394354 It is in spanish that is my native language. Ok in this presentation PONY got best good comments incluiding performance. This is the question: Some of you do have a more recently an interesting comparative

All people here agree than PONY is better to SQLALchemy ? :D :D

Hi! I think both PonyORM and SQLAlchemy have strong points :) Pony API is easier to use, and Pony is usually faster. SQLAlchemy has bigger community, working migrations and more flexibility. Regarding performance comparison you can look here:

Hey guys! I recently decided to compare the performance of pony ORM with SQLAlchemy. I posted results on Hackernoon: https://hackernoon.com/performance-testing-of-python-orms-based-on-the-tpc-c-benchmark-ae3g3yis Your feedback is very appreciated

☝️👌 thanks Alexander

I think adding .pyi files is possible

Doing that right now in a PR. I based off of orm branch.

Doing that right now in a PR. I based off of orm branch.

Ok, cool

https://mypy.readthedocs.io/en/stable/python2.html would be an alternative, but I go with .pyi files

hey there, I'm using pony orm now for the first time. As a far as I understand I just need to create my entity object in a db_session and it will trigger an insert when the session is getting closed, right?

Idk why but when I create the object nothing happens and the things that should happen after that aren't executed, the function just stops

and I don't get any message

I even have debug messages activated and tried to execute it with a debugger

but i can't see why it just stops at that point

does anyone know why that might happen?

i figured it out but i got another issue now

i created a many to one relation and it says that the Entity definition doesn't exist

For the first entities I created a many-to-one relation I didn't have this error

But for this I do, and I don't know how to fix it

class Goal(db.Entity): match = Required("Match") scorer = Required("Player") minute_scored = Required(int) composite_key(match, scorer, minute_scored) class Match(db.Entity): id = PrimaryKey(int) opponent = Required(Team) venue = Required(Venue) our_score = Optional(int) opponent_score = Optional(int) starting_at = Optional(datetime) is_full_time = Required(bool, default=False, sql_default=False) season_start = Required(int) competition = Required(str) matchday = Required(str) goals = Set("Goal")

pony.orm.core.ERDiagramError: Entity definition Goal was not found

Hi! Does Goal and Match entities belong to the same db object?

yes

but player belongs to another

could that be the problem?

All entities which have relationships should belong to the same db object

alright, i'll try to use only one db object and see if it works

i wanna define the entities in different files

is that possible?

Yes

https://stackoverflow.com/questions/51601838/ponyorm-multiple-model-files

thank you

it worked

i guess though i'm having another issue

I'm using an Enum

I created a database converter now

But I can't add it

db.provider.converter_classes.append((Enum, EnumConverter))

AttributeError: 'NoneType' object has no attribute 'converter_classes'

Converter is only a small part of what is necessary to add a type Probably you can use a simpler alternative, like class Colors: RED = 1 BLUE = 2 GREEN = 3 class Person(db.Entity): eye_color = Required(int, default=Colors.GREEN)

👍

Hello guys, I just found out about Pony and decided give it a try

And here is what I got ImportError: cannot import name 'orm' from partially initialized module 'pony' (most likely due to a circular import)

Does anybody have an idea what may cause this issue?

What Python and Pony version do you use?

Python 3.8.5 and pony 0.7.13

Yay Python3.8! Loving it! :)

Oh, I know why it's happening

I named my file for testing pony.py lol

My bad

Ah, ok

What would be an equivalent to this sql query in pony orm? I'm still having problems getting used to the syntax

sql SELECT * FROM Match WHERE season_start = (SELECT MAX(season_start) FROM Match);

Match.select(lambda m: m.season_start == max(m.season_start)).order_by(Match.starting_at)

currently i have this, but it doesn't work

I mean I could write it in sql too but I want to stick to use python for everything

… == max(m2.season_start for m2 in Match)

that makes it a subquery

that should work

thank you

In my entity I set a datetime attribute, when I get it from the db it is a str though