Peewee

This release contains a number of small fixes and enhancements.

Bugs fixed

* 606, support self-referential joins with `prefetch` and `aggregate_rows()` methods.
* 588, accomodate changes in SQLite's `PRAGMA index_list()` return value.
* 607, fixed bug where `pwiz` was not passing table names to introspector.
* 591, fixed bug with handling of named cursors in older psycopg2 version.
* Removed some cruft from the `APSWDatabase` implementation.

New features

* Added [CompressedField](http://docs.peewee-orm.com/en/latest/peewee/playhouse.html#CompressedField) and [AESEncryptedField](http://docs.peewee-orm.com/en/latest/peewee/playhouse.html#AESEncryptedField)
* 609, 610, added Django-style foreign key ID lookup. [Docs](http://docs.peewee-orm.com/en/latest/peewee/models.html#foreignkeyfield).
* Added support for [Hybrid Attributes](http://docs.peewee-orm.com/en/latest/peewee/playhouse.html#hybrid-attributes) (cool idea courtesy of SQLAlchemy).
* Added ``upsert`` keyword argument to the `Model.save()` function (SQLite only).
* 587, added support for ``ON CONFLICT`` SQLite clause for `INSERT` and `UPDATE` queries. [Docs](http://docs.peewee-orm.com/en/latest/peewee/api.html#UpdateQuery.on_conflict)
* 601, added hook for programmatically defining table names. [Model options docs](http://docs.peewee-orm.com/en/latest/peewee/models.html#model-options-and-table-metadata)
* 581, 611, support connection pools with `playhouse.db_url.connect()`. [Docs](http://docs.peewee-orm.com/en/latest/peewee/playhouse.html#connect).
* Added [Contributing section](http://docs.peewee-orm.com/en/latest/peewee/contributing.html) section to docs.

[View commits](https://github.com/coleifer/peewee/compare/2.6.0...2.6.1)

This is a tiny update, mainly consisting of a new-and-improved implementation of ``get_or_create()`` ([docs](http://docs.peewee-orm.com/en/latest/peewee/api.html#Model.get_or_create)).

Backwards-incompatible changes

* ``get_or_create()`` now returns a 2-tuple consisting of the model instance and a boolean indicating whether the instance was created. The function now behaves just like the Django equivalent.

New features

* 574, better support for setting the character encoding on Postgresql database connections. Thanks klen!
* Improved implementation of [get_or_create()](http://docs.peewee-orm.com/en/latest/peewee/api.html#Model.get_or_create).

[View commits](https://github.com/coleifer/peewee/compare/2.5.1...2.6.0)

This is a relatively small release with a few important bugfixes.

Bugs fixed

* 566, fixed a bug regarding parentheses around compound `SELECT` queries (i.e. `UNION`, `INTERSECT`, etc).
* Fixed unreported bug where table aliases were not generated correctly for compound `SELECT` queries.
* 559, add option to preserve original column order with `pwiz`. Thanks elgow!
* Fixed unreported bug where selecting all columns from a `ModelAlias` does not use the appropriate `FieldAlias` objects.

New features

* 561, added an option for bulk insert queries to return the list of auto-generated primary keys. See [docs for InsertQuery.return_id_list](http://docs.peewee-orm.com/en/latest/peewee/api.html#InsertQuery.return_id_list).
* 569, added `parse` function to the `playhouse.db_url` module. Thanks stt!
* Added [hacks](http://docs.peewee-orm.com/en/latest/peewee/hacks.html) section to the docs. Please contribute your hacks!

Backwards-incompatible changes

* Calls to `Node.in_()` and `Node.not_in()` do not take `*args` anymore and instead take a single argument.

[View commits](https://github.com/coleifer/peewee/compare/2.5.0...2.5.1)

There are a couple new features so I thought I'd bump to 2.5.x. One change Postgres users may be happy to see is the use of `INSERT ... RETURNING` to perform inserts. This should definitely speed up inserts for Postgres, since an extra query is no longer needed to get the new auto-generated primary key.

I also added a [new context manager/decorator](http://docs.peewee-orm.com/en/latest/peewee/database.html#using-multiple-databases) that allows you to use a different database for the duration of the wrapped block.

Bugs fixed

* 534, CSV utils was erroneously stripping the primary key from CSV data.
* 537, fix upserts when using `insert_many`.
* 541, respect `autorollback` with `PostgresqlExtDatabase`. Thanks davidmcclure.
* 551, fix for QueryResultWrapper's implementation of the iterator protocol.
* 554, allow SQLite journal_mode to be set at run-time.
* Fixed case-sensitivity issue with `DataSet`.

New features

* Added support for [CAST expressions](http://docs.peewee-orm.com/en/latest/peewee/playhouse.html#cast).
* Added a hook for [extending Node](http://docs.peewee-orm.com/en/latest/peewee/api.html#Node.extend) with custom methods.
* `JOIN_<type>` became `JOIN.<type>`, e.g. `.join(JOIN.LEFT_OUTER)`.
* `OP_<code>` became `OP.<code>`.
* 556, allowed using `+` and `-` prefixes to indicate ascending/descending ordering.
* 550, added [Database.initialize_connection()](http://docs.peewee-orm.com/en/latest/peewee/database.html#additional-connection-initialization) hook.
* 549, bind selected columns to a particular model. Thanks jhorman, nice PR!
* 531, support for swapping databases at run-time via [Using](http://docs.peewee-orm.com/en/latest/peewee/database.html#using-multiple-databases).
* 530, support for SQLCipher and Python3.
* New `RowIDField` for `sqlite_ext` playhouse module. This field can be used to interact with SQLite `rowid` fields.
* Added `LateralJoin` helper to the `postgres_ext` playhouse module.
* New [example blog app](https://github.com/coleifer/peewee/tree/master/examples/blog).

[View commits](https://github.com/coleifer/peewee/compare/2.4.7...2.5.0)

Bugs fixed

* 504, Docs updates.
* 506, Fixed regression in `aggregate_rows()`
* 510, Fixes bug in pwiz overwriting columns.
* 514, Correctly cast foreign keys in `prefetch()`.
* 515, Simplifies queries issued when doing recursive deletes.
* 516, Fix cloning of Field objects.
* 519, Aggregate rows now correctly preserves ordering of joined instances.
* Unreported, fixed bug to not leave expired connections sitting around in the pool.

New features

* Added support for Postgresql's ``jsonb`` type with [BinaryJSONField](http://docs.peewee-orm.com/en/latest/peewee/playhouse.html#BinaryJSONField).
* Add some basic [Flask helpers](http://docs.peewee-orm.com/en/latest/peewee/playhouse.html#flask-utils).
* Add support for `UNION ALL` queries in 512
* Add `SqlCipherExtDatabase`, which combines the sqlcipher database with the sqlite extensions.
* Add option to print metadata when generating code with ``pwiz``.

[View commits](https://github.com/coleifer/peewee/compare/2.4.6...2.4.7)

This is a relatively small release with mostly bug fixes and updates to the documentation. The one new feature I'd like to highlight is the ``ManyToManyField`` ([docs](http://docs.peewee-orm.com/en/latest/peewee/playhouse.html#ManyToManyField)).

Bugs fixed

* 503, fixes behavior of `aggregate_rows()` when used with a `CompositeKey`.
* 498, fixes value coercion for field aliases.
* 492, fixes bug with pwiz and composite primary keys.
* 486, correctly handle schemas with reflection module.

New features

* Peewee has a new [ManyToManyField](http://docs.peewee-orm.com/en/latest/peewee/playhouse.html#ManyToManyField) available in the ``playhouse.shortcuts`` module.
* Peewee now has proper support for *NOT IN* queries through the ``Node.not_in()`` method.
* Models now support iteration. This is equivalent to ``Model.select()``.

[View commits](https://github.com/coleifer/peewee/compare/2.4.5...2.4.6)