Does Pony support database migrations?

Not yet, but we are working on it. Migrations for PostgreSQL will be available really soon

I can see it has an integration with Flask. Will it has the integration with FastAPI? It’s must faster than Flask and is async.

You can use Pony with FastAPI with one caveat: you should never call async functions (with await) inside db_session

OK. I can use async for FastAPI controller and inside it can run with db_session: without-async-code-here

It looks like db migrations is the main missing part at the moment.

yes

Hi, is it possible to "stop" (rollback?) a single new instance during a db_session transaction and keeping the others? This code below doesn't seem to work, because new_game is committed to the database anyhow: for item in request_objects: try: new_game = Game() raise ValueError('You shall not pass!') except ValueError: del new_game continue

Nevermind, it works with the regular delete() method: new_game.delete()

There's a tiny spelling mistake in pony/core.py:4569 and :4582: Change attriute to attribute.

Thanks!

How can I update a record?

Select it and change values.

foo = Foo.get(attr1=...) foo.bar = 1 foo.baz = 'asd'

foo = Foo.get(attr1=...) foo.bar = 1 foo.baz = 'asd'

need?: commit()

thanks you

Not really. Pony understands where to commit

Not really. Pony understands where to commit

Clever Pony. Very clever.

Thank you for the answer

foo = Foo.get(attr1=...) foo.bar = 1 foo.baz = 'asd'

What have I done wrong? (

You need all code that uses pony objects inside a database session

Put that code within “with orm.db_session:” block

Put that code within “with orm.db_session:” block

You need all of the code that deals with pony objects in that one with block

You need all of the code that deals with pony objects in that one with block

Can I get a json object?

and how

Myobj.to_dict() then dump to JSON like any other dict

Myobj.to_dict() then dump to JSON like any other dict

thank you!

hey guys, i have a question about ponyorm with mysql i try to add a name with a emoji in it and i have set the db to varchar and i get this error pony.orm.core.UnexpectedError: Object Group[new:1] cannot be stored in the database. DataError: 1366 Incorrect string value: '\xF0\x9F\x94\x97 I...' for column 'name' at row 1 does anyone now how to ad a emoji to the db?

you need to change the mysql charset https://stackoverflow.com/questions/39463134/how-to-store-emoji-character-in-mysql-database

i tryed this but still same error

does trying to insert using a raw sql query work?

does trying to insert using a raw sql query work?

no idear never tryed a raw insert

try it

if you still have the error, you probably didn't change the collation correctly

if you still have the error, you probably didn't change the collation correctly

need to look how i need to do this

does trying to insert using a raw sql query work?

there is also no help on the website of ponyorm how explain how to raw write to database

https://docs.ponyorm.org/database.html#using-database-object-for-raw-sql-queries

Or here, more specifically: https://docs.ponyorm.org/api_reference.html#Database.execute

found the issue.. it was not mysql it was ponyorm issue, i needed to add to db.bind the charset='utf8mb4'

this did the trick

Yay! :)

thansk for the support

i try to update a value in the db, this value is edited only on 1 place in the code... why i get this error? pony.orm.core.UnrepeatableReadError: Value of User.referred_user for User[16] was updated outside of current transaction (was: None, now: User[2])

it referred to the same table

This means the following: 1) you started db_session. In this db_session you read User[16].referred_user (it was None at this moment). 2) some other transaction modified the value of User[16].referred_user 3) you updated some attribute of User[16]. At the end of db_session Pony tries to save the changes to the database, but for additional safety it checks that at this moment all fields of User[16] still have the same values as in the beginning of db_session. Pony sees that the value of User[16].referred_user was suddenly changed by other transaction from None to User[2]. As you didn't read this new value User[2] in current db_session it may be dangerous to save changes, as it may overwrite previous update. So Pony throws an exception

1 - yes i read it and it was none thats correct 2 - there is only one modified place 3 - and yes i try to update the value for None to User[2]

the group works fine only the user not

It looks like the object was modified by some concurrent transaction at the same time

Or you used raw SQL

It looks like the object was modified by some concurrent transaction at the same time

there is only one please this happend

this is the whole code

asyncio.run call does not look correct to me

the print is this

asyncio.run call does not look correct to me

that is not called but that one works fine

i disabled it to be sure.... but still not working

Use User.get_for_update instead of User.get

@metaprogrammer same error

i just notice is only for a few users

ow now if works...

was it a memory issue?

It should not be a memory issue

if i empty the db manual to test again it gives the same error again

if not user.userid == user This check will always be True, user.userid is a number, while user is an entity instance

if not user.userid == user This check will always be True, user.userid is a number, while user is an entity instance

yes i see but has this somethign to do with the error?

Probably not. I see the following possible reasons: 1) The code run in several threads or processes, and another thread/process already updated the object in the middle of db_session (but get_for_update should prevent this scenario) 2) You have some async-related error in the code, like performing async call (with await) inside db_session 3) You perform database update which Pony does not aware about, using raw SQL update or, say, a database trigger

You can use db_session(optimistic=False) to prevent Pony from detection of this type of errors, but it may just mask the real problem

Probably not. I see the following possible reasons: 1) The code run in several threads or processes, and another thread/process already updated the object in the middle of db_session (but get_for_update should prevent this scenario) 2) You have some async-related error in the code, like performing async call (with await) inside db_session 3) You perform database update which Pony does not aware about, using raw SQL update or, say, a database trigger

1 - i added this code like you sad 2 - i removed the await in the part of the code 3 - i deleted manual the value on the database (meaby thats the issue) 4 - i used also the optimistic option

Hey @metaprogrammer recently I been stuck with following issue pony.orm.core.UnrepeatableReadError: Value of Balance.balance for Balance[171] was updated outside of current transaction (was: Decimal('50001.605299999996'), now: Decimal('50001.60530000')) Problem is, I have only one transaction in code. I assumed that it happened because I was get balance object twice inside this transaction but after caching it one after it got fetched this error keeps popping up. Any idea what could be the cause? Sql debug: https://paste.ubuntu.com/p/r4hy2G5QdV/ Full error traceback: https://paste.ubuntu.com/p/9nbYpMFvxW/

Balance and address models looks like this: class Address(db.Entity): _table_ = "addresses" address = orm.Required(str, index=True) transactions = orm.Set( "Transaction", table="address_transactions", reverse="addresses" ) balances = orm.Set("Balance") class Balance(db.Entity): _table_ = "address_balances" balance = orm.Required(Decimal, precision=20, scale=8, default=0) address = orm.Required("Address") currency = orm.Required(str) orm.composite_index(address, currency)

Hi, is your application synchronous or asynchronous?

It's synchronous

Does it use threads?

Nope