It will be part of migrations, probably not necessary to have a separate issue for that

Hey guys, what is the best way to make a query that filters by se condition in a fk-related entity, but only if it exists. For instance: persons.filter(lambda person: person.dog.name == "bob"). In that case all persons without dod won't match the query. How should I modify it to include them? Why persons.filter(lambda person: not person.dog or person.dog.name == "bob") doesn't work?

Hi Mario! Sorry for the long answer. You need to use left_join for that: persons = left_join(person for person in Person) persons.filter(lambda person: not person.dog or person.dog.name == "bob")

Hi! You can specify default for attribute, but default with context is not supported: def my_function(): return randint(0, 100) class MyEntity(db.Entity): my_attr = Required(int, default=my_function) onupdate for attribute is not supported, you can try to use hooks for this: https://docs.ponyorm.org/api_reference.html#entity-hooks class MyEntity(db.Entity): my_attr = Optional(int) before_insert(self): if self.my_attr is None: self.my_attr = ... before_update(self): self.my_attr = ... Context-Sensitive Default Functions look like an interesting idea, maybe Pony should have something like that

Instead of table1 = Optional(Table1) it should be table1 = Set(Table1) because one source name can be used in multiple Table1 records

No, pony does not have such notifications. You need to implement it yourself with something like Redis

I'm about using PonyORM with aiohttp. The StackOverflow site has an answer: https://stackoverflow.com/questions/64844557/what-s-the-right-way-to-use-ponyorm-with-fastapi "To be sure everything will be okay you should use db_session as the context manager and be sure that you don't have async calls inside this block of code." But, in PonyORM documentation I find this: https://docs.ponyorm.org/transactions.html#using-db-session-with-generator-functions-or-coroutines "If inside such a generator function or coroutine you’ll try to use the db_session context manager, it will not work properly, because in Python context managers cannot intercept generator suspension. Instead, you need to wrap you generator function or coroutine with the @db_session decorator." I'm really confused! I found the following solution: https://snorfalorpagus.net/blog/2020/05/10/threaded-workers-with-aiohttp/ Is it a good idea to wrap a function with a db_session as context manager to run_in_executor, like this? executor = ThreadPoolExecutor() def add_user(): with db_session: ... async def run(executor): loop = asyncio.get_event_loop() result = await loop.run_in_executor(executor, add_user) ... Maybe there is a better solution?

Pony does not work with csv files, you need to use csv standard library to read csv file first, and then you can create Pony object for each csv row https://docs.python.org/3/library/csv.html

When will pony support async queries?

I am trying to call db.select(blah blah blah) without making use of any entity classes

Why?

Pony require entity definitions in order to make queries

maybe easiest solution is to copy pasta entity definition from the other repo. But that could cause future complications if the entity definition changes remotely

But when I launch db.generate_mapping() I would have expected to add the column to the db, while I get this error back: pony.orm.dbapiprovider.OperationalError: no such column: Person.test

You would know which is the correct method for achieve this goal?

Here because! Thanks so much 👍👍👍

It is a bit tricky to create a list of parameters for a raw SQL query if you have a list of names names = ["John", "Mike"] It is not usually a good idea to directly inject names into a query SELECT * FROM txs WHERE person.name in ('John', 'Mike') because it can lead to SQL injection vulnerability. But you can create a query that looks like this: SELECT * FROM txs WHERE person.name in ($names[0], $names[1]) And it will be protected from SQL injections. To create such a query, you can do something like name_params = ', '.join('$name[%d]' % i for i in range(names)) sql_query = """ SELECT * FROM txs WHERE person.name in (%s) """ % name_params db.execute(sql_query) Also, note that if your function receives db object from another module, where entities are defined, you can access entity classes as attributes of db object. The import of entity classes is not necessary: select(p for p in db.Person if p.name in names)