Pony Object Relational Mapper

Last update: Jan 1, 2023

Related tags

ORM mysql python orm sqlite postgresql oracle python3 cockroachdb cockroach

Overview

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Pony Object-Relational Mapper

Pony is an advanced object-relational mapper. The most interesting feature of Pony is its ability to write queries to the database using Python generator expressions and lambdas. Pony analyzes the abstract syntax tree of the expression and translates it into a SQL query.

Here is an example query in Pony:

select(p for p in Product if p.name.startswith('A') and p.cost <= 1000)

Pony translates queries to SQL using a specific database dialect. Currently Pony works with SQLite, MySQL, PostgreSQL and Oracle databases.

By providing a Pythonic API, Pony facilitates fast app development. Pony is an easy-to-learn and easy-to-use library. It makes your work more productive and helps to save resources. Pony achieves this ease of use through the following:

Compact entity definitions
The concise query language
Ability to work with Pony interactively in a Python interpreter
Comprehensive error messages, showing the exact part where an error occurred in the query
Displaying of the generated SQL in a readable format with indentation

All this helps the developer to focus on implementing the business logic of an application, instead of struggling with a mapper trying to understand how to get the data from the database.

See the example here

Support Pony ORM Development

Pony ORM is Apache 2.0 licensed open source project. If you would like to support Pony ORM development, please consider:

Become a backer or sponsor

Online tool for database design

Pony ORM also has the Entity-Relationship Diagram Editor which is a great tool for prototyping. You can create your database diagram online at https://editor.ponyorm.com, generate the database schema based on the diagram and start working with the database using declarative queries in seconds.

Documentation

Documenation is available at https://docs.ponyorm.org The documentation source is avaliable at https://github.com/ponyorm/pony-doc. Please create new documentation related issues here or make a pull request with your improvements.

License

Pony ORM is released under the Apache 2.0 license.

PonyORM community

Please post your questions on Stack Overflow. Meet the PonyORM team, chat with the community members, and get your questions answered on our community Telegram group. Join our newsletter at ponyorm.org. Reach us on Twitter.

Comments

[BUG] InterfaceError: (0, '')

Traceback (most recent call last):
  File "/usr/local/lib/python3.6/dist-packages/flask/app.py", line 1982, in wsgi_app
    response = self.full_dispatch_request()
  File "/usr/local/lib/python3.6/dist-packages/flask/app.py", line 1614, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/usr/local/lib/python3.6/dist-packages/flask/app.py", line 1517, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/usr/local/lib/python3.6/dist-packages/flask/_compat.py", line 33, in reraise
    raise value
  File "/usr/local/lib/python3.6/dist-packages/flask/app.py", line 1612, in full_dispatch_request
    rv = self.dispatch_request()
  File "/usr/local/lib/python3.6/dist-packages/flask/app.py", line 1598, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "<string>", line 2, in application_list
  File "/usr/local/lib/python3.6/dist-packages/pony/orm/core.py", line 423, in new_func
    finally: db_session.__exit__(exc_type, exc, tb)
  File "/usr/local/lib/python3.6/dist-packages/pony/orm/core.py", line 397, in __exit__
    else: rollback()
  File "<string>", line 2, in rollback
  File "/usr/local/lib/python3.6/dist-packages/pony/utils/utils.py", line 58, in cut_traceback
    return func(*args, **kwargs)
  File "/usr/local/lib/python3.6/dist-packages/pony/orm/core.py", line 326, in rollback
    transact_reraise(RollbackException, exceptions)
  File "/usr/local/lib/python3.6/dist-packages/pony/orm/core.py", line 283, in transact_reraise
    reraise(exc_class, new_exc, tb)
  File "/usr/local/lib/python3.6/dist-packages/pony/utils/utils.py", line 85, in reraise
    try: raise exc.with_traceback(tb)
  File "/usr/local/lib/python3.6/dist-packages/pony/orm/core.py", line 323, in rollback
    try: cache.rollback()
  File "/usr/local/lib/python3.6/dist-packages/pony/orm/core.py", line 1559, in rollback
    cache.close(rollback=True)
  File "/usr/local/lib/python3.6/dist-packages/pony/orm/core.py", line 1573, in close
    try: provider.rollback(connection, cache)
  File "<string>", line 2, in rollback
  File "/usr/local/lib/python3.6/dist-packages/pony/orm/dbapiprovider.py", line 59, in wrap_dbapi_exceptions
    raise InterfaceError(e)
pony.orm.core.RollbackException: InterfaceError: (0, '')

Looks like it happen when you do nothing to db for some time and then do something. For example, when script waits for http request and when it get it, pony throws the exception. If you do another request after that, everything will be ok.

I had this issue with aiohttp (but i thought that it's related to threadpool that i used) and flask.

opened by xunto 17

SQL Views

I have a db of patients and would like to use an sql view for patient search, is it possible to extend Pony to do this in my code and how(that's if pony can't do this already).
enhancement

opened by noxecane 17
Add support for calculated fields

As per this SO question, I'd like to add calculated/derived fields to my entities and then use those fields in calculations, aggregations, etc. I wasn't able to find anything in the docs or examples that indicate that this is supported. Could this kind of thing be supported in the future?

opened by tonycpsu 16

Если вызвать `.flush()` то теряется транзакционная целостность.

from pony.orm import Database, db_session

db = Database()


class TestTable(db.Entity):
    pass


def init_database():
    db.bind("sqlite", ":memory:")
    db.generate_mapping(create_tables=True)


def clear_database():
    db.drop_all_tables(with_all_data=True)
    db.create_tables()

if __name__ == "__main__":
    init_database()

    try:
        with db_session:
            entity = TestTable()
            entity.flush()
            raise ValueError()
    except ValueError as exc:
        print(exc.args)
    with db_session:
        # в транзакции ошибка, а в таблице запись уже есть!
        if len(TestTable.select()) != 0:
            print("Таблица не пуста")

    clear_database()

    try:
        with db_session:
            entity = TestTable()
            raise ValueError()
    except ValueError as exc:
        print(exc.args)
    with db_session:
        # в транзакции ошибка, а в таблице записи нет, все ок
        if len(TestTable.select()) == 0:
            print("Все в порядке!")

Что как бы очень критичный баг.

Ну и менее важная проблема - как мне получить id только что созданного элемента?

bug

opened by vladlutkov 15

How to filter query inside group statement
Title probably doesn't describe this, wasn't sure how to explain it.

Basically, I want to filter my DB columns via url parameters. With a normal select statement, I have this working fine. However I now need to run the filters on a select statement within another select statement and then call .count() on it, the following example will probably explain more.

def model_with_filters(model, aid, filters): query = select(x for x in model) for column_name, value in { k: v for k, v in filters.iteritems() if k in model._columns_ and v != ""}.iteritems(): query = query.filter("lambda x: x.%s == '%s'" % (column_name, value)) return query.filter("lambda x: x.aff_id== aid") # This is what I want to do select((a, model_with_filters(SendPin, a.aff_id, request.args).count) for a in Affiliate)

TypeError: Function 'model_with_filters' cannot be used inside query

However I am not allowed to use a function within the select query. What's the recommended way of being able to apply filters to the count statement if I can't call a function in there?

Also, using the lambdas like above seems really funky, but it's the only way I could get it to work.
question
opened by JakeAustwick 15
"db_session required" exception when working with aync def coroutines

Hey there. I'm having an issue that reminds #126 which should've been resolved. I'm also using tornado. I've managed to reproduce it with this minimal code:

https://gist.github.com/amireldor/3c7f1701761d6c92855b868e5df07af0

I wrap a coroutine (async def) with db_session but an exception is thrown when doing a database action inside the coroutine. Regular wrapped functions or with blocks are fine.

This is Python 3.6.5 and pony 0.7.6; getting "pony.orm.core.TransactionError: db_session is required when working with the database".

opened by amireldor 14
How to disconnect from db and drop all tables?
Hi, currently I am covering flask app with unit tests and I need to initialize database before each test starts and drop database after test is finished. But seems like there is no "easy" way to do it with PonyORM.

What I want is something like how it works with sqlalchemy http://pythonhosted.org/Flask-Testing/:

from flask.ext.testing import TestCase from myapp import create_app, db class MyTest(TestCase): SQLALCHEMY_DATABASE_URI = "sqlite://" TESTING = True def create_app(self): # pass in test configuration return create_app(self) def setUp(self): db.create_all() def tearDown(self): db.session.remove() db.drop_all()

Please advice: how can I disconnect from db and delete it? Is it possible?
enhancement
opened by t4ec 13
Efficient lookup in many-many relationship
I have the following schema, where the relationship between Executable and Symbol is many-to-many.

class File(db.Entity): loc = Required(str, unique=True) tim = Optional(datetime) class Executable(File): sym = Set("Symbol") class Symbol(db.Entity): sig = Required(str, 5000, encoding='utf-8') exe = Set(Executable)

A foreign-key table called Executable_Symbol would be created by Pony to store this relationship, but there seems to be no way to check whether a particular relationship exists via the ORM unless I drop down to raw SQL, i.e.

eid,sid = exe.id,sym.id db.select('* from Executable_Symbol where executable=$eid and symbol=$sid ')

I figured the best way of doing this is that if I have a Symbol called sym, and an Executable called exe, I can use the expression:

exe in sym.exe

But this seems to be very slow. In comparison, accessing the Executable_Symbol table using raw SQL is much faster, but dropping to raw SQL is not very desirable. My application would check this a few hundred thousand times, so every bit of efficiency would be useful.

Is there a better way to do this?

thanks!
enhancement
opened by chnrxn 13
generate_mapping error
I use postgres schemas.

_table_ = (schema, 'molecule')

and then I run generate_mapping(create_tables=True) on existing db with tables I receive:

DBSchemaError: Table "db_data"."molecule" cannot be created, because table "molecule" (with a different letter case) already exists in the database. Try to delete "molecule" table first.

but without schemas this works fine.
bug
opened by stsouko 12

Cannot use memcached? TransactionRolledBack, 'Object belongs to obsolete cache'

When I use memcached for cache, it throw the error:

 File "/usr/local/lib/python2.7/dist-packages/pony/orm/core.py", line 871, in __get__
    if not obj._cache_.is_alive: throw(TransactionRolledBack, 'Object belongs to obsolete cache')

How do I use the memcached?

opened by yetone 12

Integer of higher length than 11

I can't seem to find a way for pony to specify a db int field with a length > 11, so if I try and insert something longer than 11 digits, I get:

cannot be stored in the database. DataError: 1264 Out of range value for column 'xxx' at row 1

If I increase the column length manually of the database column, the same problem persists. Any ideas / suggestions?

opened by JakeAustwick 11
Wrong link in the `Parameters of db_session` documentation section

https://docs.ponyorm.org/transactions.html#parameters-of-db-session

As it was mentioned above db_session() can be used as a decorator or a context manager. It can receive parameters which are described in the API Reference.

In this paragraph for the API Reference the following link is used https://docs.ponyorm.org/transactions.html#db-session which is incorrect as the correct link is the following https://docs.ponyorm.org/api_reference.html#transactions-db-session

opened by drew2a 0
python-oracledb support.

I see the following documentation on https://docs.ponyorm.org/api_reference.html#oracle.

Pony uses the cx_Oracle driver for connecting to Oracle databases. More information about the parameters which you can use for creating a connection to Oracle database can be found here.

However, the cx-oracle is deprecated, now python-oracledb should be use instead.

Is there any plans for update the oracle driver to python-oracledb.

opened by liudonghua123 1
Support for Python 3.11

Are there any plans to support Python 3.11?

I ran my app's test suite after bumping Python from 3.9.7 to 3.11.0 and got a bunch of the following:

pony.orm.decompiling.DecompileError: Unsupported operation: RETURN_GENERATOR

opened by etseidler 6
CockroachDB support is broken due to missing method and other issues
The class PGStrConverter was removed in Jan. https://github.com/ponyorm/pony/commit/071c95c5f77c7682d185900c7630ab722011949f#diff-b703e5fd1906adc8a5be9bbe920[…]9bbbc65a48e35ce5846f0eebcf082L141

But that class is still being imported in the CockroachDB provider: https://github.com/ponyorm/pony/blob/main/pony/orm/dbproviders/cockroach.py#L20

So when using CockroachDB, it fails to import that class and crashes.

I switched to the RC release pony 0.7.15rc1 from Jan 12, 2022 which still has that method intact. But things seem still broken when running the official CockorachDB example: https://www.cockroachlabs.com/docs/stable/build-a-python-app-with-cockroachdb-pony.html#step-4-run-the-python-code

End up getting this error:

pony.orm.core.UnexpectedError: Object Account[698658240] cannot be stored in the database. ProgrammingError: value type int doesn't match type uuid of column "id" HINT: you will need to rewrite or cast the expression
opened by dikshant 0
pony.orm.dbapiprovider.OperationalError - timed out

Hi,

I implemented some ETL scripts where I partially use SQLAlchemy and for newer implementations I decided to use PonyORM. Since several weeks I have the effect that only those using PonyORM may fail, specially one. Always with the message pony.orm.dbapiprovider.OperationalError - (2003, "Can't connect to MySQL server on 'XXXXXXXXXX' (timed out)")

I rerun the script again from the command line and the message appears again. At the second manual attempt the script works as expected. Those other scripts with SQLAlchemy never fail, all of the scripts use the same MySQL server as target server.

The ETL scripts are on a plugin structure, meaning that the connection to the target DB, setting up logfiles, etc. are done within main functions, everything else (gathering data from various sources) is done from a corresponding plugin. That means that for every plugin the starting point is always the same - preparing the environment, connecting to the target, etc.

I already tried to investigate if there are network connection problems or something similar, but nothing found. I only can say that those scripts usind PonyORM may fail when trying to connect to the target.

Anyone else had a similar situation?

Regards, Thomas

opened by mosesontheweb 0

Releases(v0.7.16)

v0.7.16(Jan 27, 2022)
This is a bugfix-only release.

Bugfixes

Fixes #628: DBAPIProvider.init() got multiple values for argument 'database'

Source code(tar.gz)
Source code(zip)
pony-0.7.16-py3-none-any.whl(306.53 KB)
pony-0.7.16.tar.gz(249.23 KB)
v0.7.15(Jan 27, 2022)
Hi all! We released Pony ORM 0.7.15. This release includes:

A long-awaited support of Python 3.10.

A possibility to create shared-in memory SQLite databases that can be accessed from multiple threads

Support of Python 3.10

Previous versions of PonyORM use Python parser module from Python 2.x to parse Python AST. The support of this module was dropped in Python 3.10. Because of this, Pony ORM switches to new ast module.

With this change, the support of Python 2.7 and old versions of Python 3 was dropped, and the supported versions now are Python 3.6-Python 3.10

Shared in-memory SQLite databases

Previously in-memory SQLite databases are created in Pony ORM by specifying ":memory:" string as a database filename. The database created this way cannot be used in multiple threads. Now it is possible to use ":sharedmemory:" string to create a database that can be accessed from multiple threads.

Other changes

Do not perform optimistic checks when deleting an object (it is OK if it was already deleted by concurrent transaction)

Validation of int fields should take into account field size and check that the value is fit into the range

More tests for hybrid methods added

Fix incorrect assertion check assert t is translator.

Fix aggregated query sum(x.field for x in previous_query)

#594: Use a clearly synthetic filename when compiling dynamic code to not confuse coverage.py

Use DecompileError exception instead of AssertionError when a function cannot be decompiled

Source code(tar.gz)
Source code(zip)
pony-0.7.15-py3-none-any.whl(306.53 KB)
pony-0.7.15.tar.gz(249.18 KB)
v0.7.15rc1(Jan 10, 2022)
In this release, PonyORM got the support of Python 3.10. The code was rewritten significantly to use the standard Python ast module which comes with Python 3. Now PonyORM works on Python versions 3.7-3.10, and support of Python 2 was ended.

Bugfixes

Do not perform optimistic checks when deleting an object (it is OK if it was already deleted by concurrent transaction)

Validation of int fields should take into account field size and check that the value is fit into the range

More tests for hybrid methods added

Fix incorrect assertion check assert t is translator.

Fix aggregated query sum(x.field for x in previous_query)

#594: Use a clearly synthetic filename when compiling dynamic code to not confuse coverage.py

Use DecompileError exception instead of AssertionError when a function cannot be decompiled.

Source code(tar.gz)
Source code(zip)
v0.7.14(Nov 23, 2020)
Features

Add Python 3.9 support

Allow to use kwargs in select: Entity.select(**kwargs) and obj.collection.select(**kwargs), a feature that was announced but actually missed from 0.7.7

Add support for volatile collection attributes that don't throw "Phantom object appeared/disappeared" exceptions

Bugfixes

Fix negative timedelta conversions

Pony should reconnect to PostgreSQL when receiving 57P01 error (AdminShutdown)

Allow mixing compatible types (like int and float) in coalesce() arguments

Support of subqueries in coalesce() arguments

Fix using aggregated subqueries in ORDER BY section

Fix queries with expressions like (x, y) in ((a, b), (c, d))

#451: KeyError for seeds with unique attributes in SessionCache.update_simple_index()

Source code(tar.gz)
Source code(zip)
v0.7.13(Mar 3, 2020)

This release contains no new features or bugfixes. The only reason for this release is to test our CI/CD process.
Source code(tar.gz)
Source code(zip)
v0.7.12(Feb 4, 2020)
Features

CockroachDB support added

CI testing for SQLite, PostgreSQL & CockroachDB

Bugfixes

Fix translation of getting array items with negative indexes

Fix string getitem translation for slices and negative indexes

PostgreSQL DISTINCT bug fixed for queries with ORDER BY clause

Fix date difference syntax in PostgreSQL

Fix casting json to dobule in PostgreSQL

Fix count by several columns in PostgreSQL

Fix PostgreSQL MIN and MAX expressions on boolean columns

Fix determination of interactive mode in PyCharm

Fix column definition when sql_default is specified: DEFAULT should be before NOT NULL

Relax checks on updating in-memory cache indexes (don't throw CacheIndexError on valid cases)

Fix deduplication logic for attribute values

Source code(tar.gz)
Source code(zip)
v0.7.11(Oct 23, 2019)
Features

#472: Python 3.8 support

Support of hybrid functions (inlining simple Python functions into query)

#438: support datetime-datetime, datetime-timedelta, datetime+timedelta in queries

Bugfixes

#430: add ON DELETE CASCADE for many-to-many relationships

#465: Should reconnect to MySQL on OperationalError 2013 'Lost connection to MySQL server during query'

#468: Tuple-value comparisons generate incorrect queries

#470 fix PendingDeprecationWarning of imp module

Fix incorrect unpickling of objects with Json attributes

Check value of discriminator column on object creation if set explicitly

Correctly handle Flask current_user proxy when adding new items to collections

Some bugs in syntax of aggregated queries were fixed

Fix syntax of bulk delete queries

Bulk delete queries should clear query results cache so next select will get correct result from the database

Fix error message when hybrid method is too complex to decompile

Source code(tar.gz)
Source code(zip)
v0.7.10(Apr 20, 2019)
Bugfixes

Python3.7 and PyPy decompiling fixes

Fix reading NULL from Optional nullable array column

Fix handling of empty arrays in queries

#415: error message typo

#432: PonyFlask - request object can trigger teardown_request without real request

Fix GROUP CONCAT separator for MySQL

Source code(tar.gz)
Source code(zip)
v0.7.9(Jan 21, 2019)
Bugfixes

Fix handling of empty arrays and empty lists in queries

Fix reading optional nullable array columns from database

Source code(tar.gz)
Source code(zip)
v0.7.8(Jan 19, 2019)
This is a bug fix release

Bugfixes

#414: prefetching Optional relationships fails on 0.7.7

Fix a bug caused by incorrect deduplication of column values

Source code(tar.gz)
Source code(zip)
0.7.7(Jan 17, 2019)
Major features

Array type support for PostgreSQL and SQLite

isinstance() support in queries

Support of queries based on collections: select(x for x in y.items)

Other features

Support of Entity.select(**kwargs)

Support of SKIP LOCKED option in 'SELECT ... FOR UPDATE'

New function make_proxy(obj) to make cros-db_session proxy objects

Specify ON DELETE CASCADE/SET NULL in foreign keys

Support of LIMIT in SELECT FROM (SELECT ...) type of queries

Support for negative JSON array indexes in SQLite

Improvements

Improved query prefetching: use fewer number of SQL queries

Memory optimization: deduplication of values recieved from the database in the same session

increase DBAPIProvider.max_params_count value

Bugfixes

#405: breaking change with cx_Oracle 7.0: DML RETURNING now returns a list

#380: db_session should work with async functions

#385: test fails with python3.6

#386: release unlocked lock error in SQLite

#390: TypeError: writable buffers are not hashable

#398: add auto coversion of numpy numeric types

#404: GAE local run detection

Fix Flask compatibility: add support of LocalProxy object

db_session(sql_debug=True) should log SQL commands also during db_session.exit()

Fix duplicated table join in FROM clause

Fix accessing global variables from hybrid methods and properties

Fix m2m collection loading bug

Fix composite index bug: stackoverflow.com/questions/53147694

Fix MyEntity[obj.get_pk()] if pk is composite

MySQL group_concat_max_len option set to max of 32bit platforms to avoid truncation

Show all attribute options in show(Entity) call

For nested db_session retry option should be ignored

Fix py_json_unwrap

Other minor fixes

Source code(tar.gz)
Source code(zip)
0.7.6(Aug 10, 2018)
Features since 0.7.5:

f-strings support in queries: select(f'{s.name} - {s.age}' for s in Student)

#344: It is now possible to specify offset without limit: query.limit(offset=10)

#371: Support of explicit casting of JSON expressions to str, int or float

@db.on_connect decorator added

Bugfixes

Fix bulk delete bug introduced in 0.7.4

#370 Fix memory leak introduced in 0.7.4

Now exists() in query does not throw away condition in generator expression: exists(s.gpa > 3 for s in Student)

#373: 0.7.4/0.7.5 breaks queries using the in operator to test membership of another query result

#374: auto=True can be used with all PrimaryKey types, not only int

#369: Make QueryResult looks like a list object again: add concatenation with lists, .shuffle() and .to_list() methods

#355: Fix binary primary keys PrimaryKey(buffer) in Python2

Interactive mode support for PyCharm console

Fix wrong table aliases in complex queries

Fix query optimization code for complex queries

Fix a bug with hybrid properties that use external functions

Source code(tar.gz)
Source code(zip)
0.7.6rc1(Aug 8, 2018)
This is mostly bugfix release to fix bugs introduced in 0.7.4

New features

f-strings support in queries: select(f'{s.name} - {s.age}' for s in Student)

#344: It is now possible to specify offset without limit: query.limit(offset=10)

#371: Support of explicit casting of JSON expressions to str, int or float

#367: @db.on_connect decorator added

Bugfixes

Fix bulk delete bug introduced in 0.7.4

#370 Fix memory leak introduced in 0.7.4

Now exists() in query does not throw away condition in generator expression: exists(s.gpa > 3 for s in Student)

#373: 0.7.4/0.7.5 breaks queries using the in operator to test membership of another query result

#374: auto=True can be used with all PrimaryKey types, not only int

#369: Make QueryResult looks like a list object again: add concatenation with lists, .shuffle() and .to_list() methods

#355: Fix binary primary keys PrimaryKey(buffer) in Python2

Interactive mode support for PyCharm console

Fix wrong table aliases in complex queries

Fix query optimization code for complex queries

Source code(tar.gz)
Source code(zip)
0.7.5(Jul 24, 2018)
Bugfixes

query.where and query.filter method bug introduced in 0.7.4 was fixed

Source code(tar.gz)
Source code(zip)
0.7.4(Jul 23, 2018)
Major features

Hybrid methods and properties added: https://docs.ponyorm.com/entities.html#hybrid-methods-and-properties

Allow to base queries on another queries: select(x.a for x in prev_query if x.b)

Added support of Python 3.7

Added support of PyPy

group_concat() aggregate function added

pony.flask subpackage added for integration with Flask

Other features

distinct option added to aggregate functions

Support of explicit casting to float and bool in queries

Improvements

Apply @cut_traceback decorator only when pony.MODE is 'INTERACTIVE'

Bugfixes

In SQLite3 LIKE is case sensitive now

#249: Fix incorrect mixin used for Timedelta

#251: correct dealing with qualified table names

#301: Fix aggregation over JSON Column

#306: Support of frozenset constants added

#308: Fixed an error when assigning JSON attribute value to the same attribute: obj.json_attr = obj.json_attr

#313: Fix missed retry on exception raised during db_session.__exit__

#314: Fix AttributeError: 'NoneType' object has no attribute 'seeds'

#315: Fix attribute lifting for JSON attributes

#321: Fix KeyError on obj.delete()

#325: duplicating percentage sign in raw SQL queries without parameters

#331: Overriding __len__ in entity fails

#336: entity declaration serialization

#357: reconnect after PostgreSQL server closed the connection unexpectedly

Fix Python implementation of between() function and rename arguments: between(a, x, y) -> between(x, a, b)

Fix retry handling: in PostgreSQL and Oracle an error can be raised during commit

Fix optimistic update checks for composite foreign keys

Don't raise OptimisticCheckError if db_session is not optimistic

Handling incorrect datetime values in MySQL

Improved ImportError exception messages when MySQLdb, pymysql, psycopg2 or psycopg2cffi driver was not found

desc() function fixed to allow reverse its effect by calling desc(desc(x))

__contains__ method should check if objects belong to the same db_session

Fix pony.MODE detection; mod_wsgi detection according to official doc

A lot of inner fixes

Source code(tar.gz)
Source code(zip)
0.7.3(Oct 23, 2017)
New features

where() method added to query

coalesce() function added

between(x, a, b) function added

#295: Add _table_options_ for entity class to specify engine, tablespace, etc.

Make debug flag thread-local

sql_debugging context manager added

sql_debug and show_values arguments to db_session added

set_sql_debug function added as alias to (to be deprecated) sql_debug function

Allow db_session to accept ddl parameter when used as context manager

Add optimistic=True option to db_session

Skip optimistic checks for queries in db_session with serializable=True

fk_name option added for attributes in order to specify foreign key name

#280: Now it's possible to specify timeout option, as well as pass other keyword arguments for sqlite3.connect function

Add support of explicit casting to int in queries using int() function

Added modulo division % native support in queries

Bugfixes

Fix bugs with composite table names

Fix invalid foreign key & index names for tables which names include schema name

For queries like select(x for x in MyObject if not x.description) add "OR x.info IS NULL" for nullable string columns

Add optimistic checking for delete() method

Show updated attributes when OptimisticCheckError is being raised

Fix incorrect aliases in nested queries

Correctly pass exception from user-defined functions in SQLite

More clear error messages for UnrepeatableReadError

Fix db_session(strict=True) which was broken in 2d3afb24

Fixes #170: Problem with a primary key column used as a part of another key

Fixes #223: incorrect result of getattr(entity, attrname) when the same lambda applies to different entities

Fixes #266: Add handler to "pony.orm" logger does not work

Fixes #278: Cascade delete error: FOREIGN KEY constraint failed, with complex entity relationships

Fixes #283: Lost Json update immediately after object creation

Fixes #284: query.order_by() orders Json numbers like strings

Fixes #288: Expression text parsing issue in Python 3

Fixes #293: translation of if-expressions in expression

Fixes #294: Real stack traces swallowed within IPython shell

Collection.count() method should check if session is alive

Set obj._session_cache_ to None after exiting from db session for better garbage collection

Unload collections which are not fully loaded after exiting from db session for better garbage collection

Raise on unknown options for attributes that are part of relationship

Source code(tar.gz)
Source code(zip)
0.7.2(Jul 17, 2017)
New features

All arguments of db.bind() can be specified as keyword arguments. Previously Pony required the first positional argument which specified the database provider. Now you can pass all the database parameters using the dict: db.bind(**db_params). See https://docs.ponyorm.com/api_reference.html#Database.bind

The optimistic attribute option is added https://docs.ponyorm.com/api_reference.html#cmdoption-arg-optimistic

Bugfixes

Fixes #219: when a database driver raises an error, sometimes this error was masked by the 'RollbackException: InterfaceError: connection already closed' exception. This happened because on error, Pony tried to rollback transaction, but the connection to the database was already closed and it masked the initial error. Now Pony displays the original error which helps to understand the cause of the problem.

Fixes #276: Memory leak

Fixes the all declaration. Previously IDEs, such as PyCharm, could not understand what is going to be imported by 'from pony.orm import *'. Now it works fine.

Fixes #232: negate check for numeric expressions now checks if value is zero or NULL

Fixes #238, fixes #133: raise TransactionIntegrityError exception instead of AssertionError if obj.collection.create(**kwargs) creates a duplicate object

Fixes #221: issue with unicode json path keys

Fixes bug when discriminator column is used as a part of a primary key

Handle situation when SQLite blob column contains non-binary value

Source code(tar.gz)
Source code(zip)
0.7.1(Jan 10, 2017)
New features

New warning DatabaseContainsIncorrectEmptyValue added, it is raised when the required attribute is empty during loading an entity from the database

Bugfixes

Fixes #216: Added Python 3.6 support

Fixes #203: subtranslator should use argnames from parent translator

Change a way aliases in SQL query are generated in order to fix a problem when a subquery alias masks a base query alias

Volatile attribute bug fixed

Fix creation of self-referenced foreign keys - before this Pony didn't create the foreign key for self-referenced attributes

Bug fixed: when required attribute is empty the loading from the database shouldn't raise the validation error. Now Pony raises the warning DatabaseContainsIncorrectEmptyValue

Throw an error with more clear explanation when a list comprehension is used inside a query instead of a generator expression: "Use generator expression (... for ... in ...) instead of list comprehension [... for ... in ...] inside query"

Source code(tar.gz)
Source code(zip)
0.7(Oct 11, 2016)
Starting with this release Pony ORM is release under the Apache License, Version 2.0.

New features

Added getattr() support in queries: https://docs.ponyorm.com/api_reference.html#getattr

Backward incompatible changes

#159: exceptions happened during flush() should not be wrapped with CommitException

Before this release an exception that happened in a hook(https://docs.ponyorm.com/api_reference.html#entity-hooks), could be raised in two ways - either wrapped into the CommitException or without wrapping. It depended if the exception happened during the execution of flush() or commit() function on the db_session exit. Now the exception happened inside the hook never will be wrapped into the CommitException.

Bugfixes

#190: Timedelta is not supported when using pymysql

Source code(tar.gz)
Source code(zip)
0.6.6(Aug 22, 2016)
New features

Added native JSON data type support in all supported databases: https://docs.ponyorm.com/json.html

Backward incompatible changes

Dropped Python 2.6 support

Improvements

#179 Added the compatibility with PYPY using psycopg2cffi

Added an experimental @db_session strict parameter: https://docs.ponyorm.com/transactions.html#strict

Bugfixes

#182 - LEFT JOIN doesn't work as expected for inherited entities when foreign key is None

Some small bugs were fixed

Source code(tar.gz)
Source code(zip)
0.6.5(Apr 4, 2016)
Improvements

Fixes #172: Query prefetch() method should load specified lazy attributes right in the main query if possible

Bugfixes

Fixes #168: Incorrect caching when slicing the same query multiple times

Fixes #169: When py_check() returns False, Pony should truncate too large values in resulting ValueError message

Fixes #171: AssertionError when saving changes of multiple objects

Fixes #176: Autostripped strings are not validated correctly for Required attributes

See blog post for more detailed information: https://blog.ponyorm.com/2016/04/04/pony-orm-release-0-6-5/
Source code(tar.gz)
Source code(zip)
0.6.4(Feb 10, 2016)
Pony ORM Release 0.6.4 (2016-02-10)

This release brings no new features, has no backward incompatible changes, only bug fixes. If you are using obj.flush() method in your code we recommend you to upgrade to 0.6.4 release.

Fixed #161: 0.6.3 + obj.flush(): after_insert, after_update & after_delete hooks do not work

Source code(tar.gz)
Source code(zip)
0.6.3(Feb 5, 2016)
This release was intended to fix the behavior of obj.flush(), but failed to do it in a proper way. Please skip this release and update to 0.6.4 if you are using obj.flush() method.

Fixed #138: Incorrect behavior of obj.flush(): assertion failed after exception

Fixed #157: Incorrect transaction state after obj.flush() caused “release unlocked lock” error in SQLite

Fixed #151: SQLite + upper() or lower() does not work as expected

#138: Incorrect behavior of obj.flush(): assertion failed after exception,

#157: Incorrect transaction state after obj.flush() caused “release unlocked lock” error in SQLite

These are long-standing bugs, but they were discovered just recently. The bugs were caused by incorrect implementation of obj.flush() method. In the same time the global flush() function worked correctly. Before this fix the method obj.flush() didn’t call before_xxx and after_xxx hooks. In some cases it led to assertion error or some other errors when using SQLite.

Now both bugs are fixed and the method obj.flush() works properly.

#151: SQLite + upper() or lower() does not work as expected

Since SQLite does not support Unicode operations, the upper() and lower() SQL functions do not work for non-ascii symbols.

Starting with this release Pony registers two additional unicode-aware functions in SQLite: py_upper() and py_lower(), and uses these functions instead of the standard upper() and lower() functions:

>>> select(p.id for p in Person if p.name.upper() == 'John')[:]

SQLite query:

SELECT "p"."id" FROM "Person" "p" WHERE py_upper("p"."name") = 'John'

For other databases Pony still uses standard upper() and lower() functions.
Source code(tar.gz)
Source code(zip)
0.6.2(Jan 11, 2016)
Pony ORM Release 0.6.2 (2016-01-11)

Blogpost: https://blog.ponyorm.com/2016/01/11/pony-orm-release-0-6-2/

The documentation was moved from this repo to a separate one at https://github.com/ponyorm/pony-doc The compiled version can be found at https://docs.ponyorm.com

New features

Python 3.5 support

#132, #145: raw_sql() function was added

#126: Ability to use @db_session with generator functions

#116: Add support to select by UUID

Ability to get string SQL statement using the Query.get_sql() method

New function delete(gen) and Query.delete(bulk=False)

Now it is possible to override Entity.init() and declare custom entity methods

Backward incompatible changes

Normalizing table names for symmetric relationships

Autostrip - automatically remove leading and trailing characters

Bugfixes

#87: Pony fails with pymysql installed as MySQLdb

#118: Pony should reconnect if previous connection was created before process was forked

#121: Unable to update value of unique attribute

#122: AssertionError when changing part of a composite key

#127: a workaround for incorrect pysqlite locking behavior

#136: Cascade delete does not work correctly for one-to-one relationships

#141, #143: remove restriction on adding new methods to entities

#142: Entity.select_random() AssertionError

#147: Add 'atom_expr' symbol handling for Python 3.5 grammar

Source code(tar.gz)
Source code(zip)
0.6.1(Feb 20, 2015)
Closed #65: Now the select(), filter(), order_by(), page(), limit(), random() methods can be applied to collection attributes

Closed #105: Now you can pass globals and locals to the select() function

Improved inheritance support in queries: select(x for x in BaseClass if x.subclass_attr == y)

Now it is possible to do db.insert(SomeEntity, column1=x, column2=y) instead of db.insert(SomeEntity._table_, column1=x, column2=y)

Discriminator attribute can be part of the composite index

Now it is possible to specify the attribute name instead of the attribute itself in composite index

Query statistics: global_stats_lock is deprecated, just use global_stats property without any locking

New load() method for entity instances which retrieves all unloaded attributes except collections

New load() method for collections, e.g. customer.orders.load()

Enhanced error message when descendant classes declare attributes with the same name

Fixed #98: Composite index can include attributes of base entity

Fixed #106: incorrect loading of object which consists of primary key only

Fixed pony.converting.check_email()

Prefetching bug fixed: if collection is already fully loaded it shouldn't be loaded again

Deprecated Entity.order_by(..) method was removed. Use Entity.select().order_by(...) instead

Various performance enhancements

Multiple bugs were fixed

Source code(tar.gz)
Source code(zip)
0.6(Nov 5, 2014)
Changes since Pony ORM 0.6rc3:

Fixed #94: Aggregated subquery bug fixed

Short description

Official support of Python 3 added!

As a string attribute type, use str instead of unicode for compatibility with Python 3

Use int with size=64 option instead of long for compatibility with Python 3

In Python 3, use pure-python pymysql adapter instead of MySQLdb

Multiple bugfixes and optimizations since 0.5.4 release

Full description:

http://blog.ponyorm.com/2014/11/05/pony-orm-release-0-6/
Source code(tar.gz)
Source code(zip)
0.6rc3(Oct 30, 2014)
Bugfixes

Fixed #18: Allow to specify size and unsigned for int type

Fixed #77: Discriminate Pony-generated fields in entities: Attribute.is_implicit field added

Fixed #83: Entity.get() should issue LIMIT 2 when non-unique criteria used for search

Fixed #84: executing db.insert() should turn off autocommit and begin transaction

Fixed #88: composite_index(*attrs) added to support non-unique composite indexes

Fixed #89: IN / NOT IN clauses works different with empty sequence

Fixed #90: Do not automatically add "distinct" if query.first() used

Fixed #91: document automatic "distinct" behaviour and also .without_distinct()

Fixed #92: without_distinct() and first() do not work together correctly

Deprecation of attribute long type

size and unsigned options for int attributes link

Since the long type has gone in Python 3, the long type is deprecated in Pony now. Instead of long you should use the int type and specify the size option:

class MyEntity(db.Entity): attr1 = Required(long) # deprecated attr2 = Required(int, size=64) # new way for using BIGINT type in the database
Source code(tar.gz)
Source code(zip)
0.6rc2(Oct 10, 2014)

This release fixes syntax errors during installation on ubuntu 14.04 (issue #81)
Source code(tar.gz)
Source code(zip)
0.6rc1(Oct 8, 2014)
Blog post: http://blog.ponyorm.com/2014/10/08/pony-orm-0-6-release-candidate-1

New features:

Python 3 support

pymysql adapter support for MySQL databases

Backward incompatible changes

Now Pony treats both str and unicode attribute types as they are unicode strings in both Python 2 and 3. So, the attribute declaration attr = Required(str) is equal to attr = Required(unicode) in Python 2 and 3. The same thing is with LongStr and LongUnicode - both of them are represented as unicode strings now.

For the sake of backward compatibility Pony adds unicode as an alias to str and buffer as an alias to bytes in Python 3.

Other changes and bug fixes

Fixes #74: Wrong FK column type when using sql_type on foreign ID column

Fixes #75: MappingError for self-referenced entities in a many-to-many relationship

Fixes #80: “Entity NoneType does not belong to database” when using to_dict

Source code(tar.gz)
Source code(zip)
0.5.4(Sep 22, 2014)
New functions and methods:

pony.orm.serialization module with the to_dict() and to_json() functions was added. Before this release you could use the to_dict() method of an entity instance in order to get a key-value dictionary structure for a specific entity instance. Sometimes you might need to serialize not only the instance itself, but also the instance's related objects. In this case you can use the to_dict() function from the pony.orm.serialization module.

to_dict() - receives an entity instance or a list of instances and returns a dictionary structure which keeps the passed object(s) and immediate related objects

to_json() – uses to_dict() and returns JSON representation of the to_dict() result

Query.prefetch() – allows to specify which related objects or attributes should be loaded from the database along with the query result . Example:

select(s for s in Student).prefetch(Group, Department, Student.courses)

obj.flush() – allows flush a specific entity to the database

obj.get_pk() – return the primary key value for an entity instance

py_check parameter for attributes added. This parameter allows you to specify a function which will be used for checking the value before it is assigned to the attribute. The function should return True/False or can raise ValueError exception if the check failed. Example:

class Student(db.Entity): name = Required(unicode) gpa = Required(float, py_check=lambda val: val >= 0 and val <= 5)

New types:

time and timedelta – now you can use these types for attribute declaration. Also you can use timedelta and a combination of datetime + timedelta types inside queries.

New hooks:

after_insert, after_update, after_delete - these hooks are called when an object was inserted, updated or deleted in the database respectively (link)

New features:

Added support for pymysql – pure Python MySQL client. Currently it is used as a fallback for MySQLdb interface

Other changes and bug fixes

obj.order_by() method is deprecated, use Entity.select().order_by() instead

obj.describe() now displays composite primary keys

Fixes #50: PonyORM does not escape _ and % in LIKE queries

Fixes #51: Handling of one-to-one relations in declarative queries

Fixes #52: An attribute without a column should not have rbits & wbits

Fixes #53: Column generated at the wrong side of "one-to-one" relationship

Fixes #55: obj.to_dict() should do flush at first if the session cache is modified

Fixes #57: Error in to_dict() when to-one attribute value is None

Fixes #70: EntitySet allows to add and remove None

Check that the entity name starts with a capital letter and throw exception if it is not then raise the ERDiagramError: Entity class name should start with a capital letter exception

Source code(tar.gz)
Source code(zip)

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Releases(v0.7.16)

v0.7.16(Jan 27, 2022)

Bugfixes

v0.7.15(Jan 27, 2022)

Support of Python 3.10

Shared in-memory SQLite databases

Other changes

v0.7.15rc1(Jan 10, 2022)

Bugfixes

v0.7.14(Nov 23, 2020)

Features

Bugfixes

v0.7.13(Mar 3, 2020)

v0.7.12(Feb 4, 2020)

Features

Bugfixes

v0.7.11(Oct 23, 2019)

Features

Bugfixes

v0.7.10(Apr 20, 2019)

Bugfixes

v0.7.9(Jan 21, 2019)

Bugfixes

v0.7.8(Jan 19, 2019)

Bugfixes

0.7.7(Jan 17, 2019)

Major features

Other features

Improvements

Bugfixes

0.7.6(Aug 10, 2018)

Features since 0.7.5:

Bugfixes

0.7.6rc1(Aug 8, 2018)

New features

Bugfixes

0.7.5(Jul 24, 2018)

Bugfixes

0.7.4(Jul 23, 2018)

Major features

Other features

Improvements

Bugfixes

0.7.3(Oct 23, 2017)

New features

Bugfixes

0.7.2(Jul 17, 2017)

New features

Bugfixes

0.7.1(Jan 10, 2017)

New features

Bugfixes

0.7(Oct 11, 2016)

New features

Backward incompatible changes

Bugfixes

0.6.6(Aug 22, 2016)

New features

Backward incompatible changes

Improvements

Bugfixes

0.6.5(Apr 4, 2016)

Improvements

Bugfixes

0.6.4(Feb 10, 2016)

Pony ORM Release 0.6.4 (2016-02-10)

0.6.3(Feb 5, 2016)

#138: Incorrect behavior of obj.flush(): assertion failed after exception,

#157: Incorrect transaction state after obj.flush() caused “release unlocked lock” error in SQLite

Deprecation of attribute `long` type