django-mysql 2.3.0

Extensions to Django for use with MySQL/MariaDB

The dolphin-pony - proof that cute + cute = double cute.

Django-MySQL is a non-inventively named package that helps you use some MySQL/MariaDB-specific features in the world of Django.

What kind of features?

Includes:

• QuerySet extensions:
  • ‘Smart’ iteration - chunked pagination across a large queryset
  • approx_count for quick estimates of count()
  • Query hints
  • Quick pt-visual-explain of the underlying query
• Model fields:
  • MySQL 5.7+ JSON Field
  • MariaDB Dynamic Columns for storing dictionaries
  • Comma-separated fields for storing lists and sets
  • ‘Missing’ fields: differently sized BinaryField/TextField classes, BooleanFields represented by BIT(1)
• ORM expressions for over 20 MySQL-specific functions
• A new cache backend that makes use of MySQL’s upsert statement and does compression
• Handler API for quicker-than-SQL reads using the ‘NoSQL’ HANDLER commands
• Status variable inspection and utility methods
• Named locks for easy locking of e.g. external resources
• Table lock manager for hard to pull off data migrations

To see them all, check out the exposition at https://django-mysql.readthedocs.io/en/latest/exposition.html .

Requirements and Installation

Please see https://django-mysql.readthedocs.io/en/latest/installation.html .

Documentation

Every detail documented on Read The Docs.

History

Pending

2.3.0 (2018-06-19)

• Started testing with MariaDB 10.3.
• Changed GlobalStatus.wait_until_load_low() to increase the default number of allowed running threads from 5 to 10, to account for the new default threads in MariaDB 10.3.
• Added encoder and decoder arguments to JSONField for customizing the way JSON is encoded and decoded from the database.
• Added a touch method to the MySQLCache to refresh cache keys, as added in Django 2.1.
• Use a temporary database connection in system checks to avoid application startup stalls.

2.2.2 (2018-04-24)

• Fixed some crashes from DynamicField instances without explicit spec definitions.
• Fixed a crash in system checks for ListCharField and SetCharField instances missing max_length.

2.2.1 (2018-04-14)

• Fixed JSONField.deconstruct() to not break the path for subclasses.

2.2.0 (2017-12-04)

• Add output_field argument to JSONExtract function.
• Improved DB version checks for JSONField and DynamicField so you can have just one connection that supports them.
• Django 2.0 compatibility.

2.1.1 (2017-10-10)

• Changed subprocess imports for compatibility with Google App Engine.
• (Insert new release notes below this line)
• Made MySQLCache.set_many return a list as per Django 2.0.

2.1.0 (2017-06-11)

• Django 1.11 compatibility
• Some fixes to work with new versions of mysqlclient

2.0.0 (2017-05-28)

• Fixed JSONField model field string serialization. This is a small backwards incompatible change.

  Storing strings mostly used to crash with MySQL error -1 “error totally whack”, but in the case your string was valid JSON, it would store it as a JSON object at the MySQL layer and deserialize it when returned. For example you could do this:

  >>> mymodel.attrs = '{"foo": "bar"}'
  >>> mymodel.save()
  >>> mymodel = MyModel.objects.get(id=mymodel.id)
  >>> mymodel.attrs
  {'foo': 'bar'}
  

  The new behaviour now correctly returns what you put in:

  >>> mymodel.attrs
  '{"foo": "bar"}'
  

• Removed the connection.is_mariadb monkey patch. This is a small backwards incompatible change. Instead of using it, use django_mysql.utils.connection_is_mariadb.

1.2.0 (2017-05-14)

• Only use Django’s vendored six (django.utils.six). Fixes usage of EnumField and field lookups when six is not installed as a standalone package.
• Added JSONInsert, JSONReplace and JSONSet database functions that wraps the respective JSON-modifying functions from MySQL 5.7.
• Fixed JSONField to work with Django’s serializer framework, as used in e.g. dumpdata.
• Fixed JSONField form field so that it doesn’t overquote inputs when redisplaying the form due to invalid user input.

1.1.1 (2017-03-28)

• Don’t allow NaN in JSONField because MySQL doesn’t support it

1.1.0 (2016-07-22)

• Dropped Django 1.7 support
• Made the query hint functions raise RuntimeError if you haven’t activated the query-rewriting layer in settings.

1.0.9 (2016-05-12)

• Fixed some features to work when there are non-MySQL databases configured
• Fixed JSONField to allow control characters, which MySQL does - but not in a top-level string, only inside a JSON object/array.

1.0.8 (2016-04-08)

• SmartChunkedIterator now fails properly for models whose primary key is a non-integer foreign key.
• pty is no longer imported at the top-level in django_mysql.utils, fixing Windows compatibility.

1.0.7 (2016-03-04)

• Added new JSONField class backed by the JSON type added in MySQL 5.7.
• Added database functions JSONExtract, JSONKeys, and JSONLength that wrap the JSON functions added in MySQL 5.7, which can be used with the JSON type columns as well as JSON data held in text/varchar columns.
• Added If database function for simple conditionals.

1.0.6 (2016-02-26)

• Now MySQL 5.7 compatible
• The final message from SmartChunkedIterator is now rounded to the nearest second.
• Lock and TableLock classes now have acquire and release() methods for using them as normal objects rather than context managers

1.0.5 (2016-02-10)

• Added manage.py command fix_datetime_columns that outputs the SQL necessary to fix any datetime columns into datetime(6), as required when upgrading a database to MySQL 5.6+, or MariaDB 5.3+.
• SmartChunkedIterator output now includes the total time taken and number of objects iterated over in the final message.

1.0.4 (2016-02-02)

• Fixed the new system checks to actually work

1.0.3 (2016-02-02)

• Fixed EnumField so that it works properly with forms, and does not accept the max_length argument.
• SmartChunkedIterator output has been fixed for reversed iteration, and now includes a time estimate.
• Added three system checks that give warnings if the MySQL configuration can (probably) be improved.

1.0.2 (2016-01-24)

• New function add_QuerySetMixin allows addding the QuerySetMixin to arbitrary QuerySets, for when you can’t edit a model class.
• Added field class EnumField that uses MySQL’s ENUM data type.

1.0.1 (2015-11-18)

• Added chunk_min argument to SmartChunkedIterator

1.0.0 (2015-10-29)

• Changed version number to 1.0.0 to indicate maturity.
• Added DynamicField for using MariaDB’s Named Dynamic Columns, and related database functions ColumnAdd, ColumnDelete, and ColumnGet.
• SmartChunkedIterator with report_progress=True correctly reports ‘lowest pk so far’ when iterating in reverse.
• Fix broken import paths during deconstruct() for subclasses of all fields: ListCharField, ListTextField, SetCharField, SetTextField, SizedBinaryField and SizedTextField
• Added XML database functions - UpdateXML and XMLExtractValue.

0.2.3 (2015-10-12)

• Allow approx_count on QuerySets for which only query hints have been used
• Added index query hints to QuerySet methods, via query-rewriting layer
• Added ordering parameter to GroupConcat to specify the ORDER BY clause
• Added index query hints to QuerySet methods, via query-rewriting layer
• Added sql_calc_found_rows() query hint that calculates the total rows that match when you only take a slice, which becomes available on the found_rows attribute
• Made SmartChunkedIterator work with reverse()’d QuerySets

0.2.2 (2015-09-03)

• SmartChunkedIterator now takes an argument chunk_size as the initial chunk size
• SmartChunkedIterator now allows models whose primary key is a ForeignKey
• Added iter_smart_pk_ranges which is similar to iter_smart_chunks but yields only the start and end primary keys for each chunks, in a tuple.
• Added prefix methods to MySQLCache - delete_with_prefix, get_with_prefix, keys_with_prefix
• Added Bit1BooleanField and NullBit1BooleanField model fields that work with boolean fields built by other databases that use the BIT(1) column type

0.2.1 (2015-06-22)

• Added Regexp database functions for MariaDB - RegexpInstr, RegexpReplace, and RegexpSubstr
• Added the option to not limit the size of a MySQLCache by setting MAX_ENTRIES = -1.
• MySQLCache performance improvements in get, get_many, and has_key
• Added query-rewriting layer added which allows the use of MySQL query hints such as STRAIGHT_JOIN via QuerySet methods, as well as adding label comments to track where queries are generated.
• Added TableLock context manager

0.2.0 (2015-05-14)

• More database functions added - Field and its complement ELT, and LastInsertId
• Case sensitive string lookup added as to the ORM for CharField and TextField
• Migration operations added - InstallPlugin, InstallSOName, and AlterStorageEngine
• Extra ORM aggregates added - BitAnd, BitOr, and BitXor
• MySQLCache is now case-sensitive. If you are already using it, an upgrade ALTER TABLE and migration is provided at the end of the cache docs.
• (MariaDB only) The Lock class gained a class method held_with_prefix to query held locks matching a given prefix
• SmartIterator bugfix for chunks with 0 objects slowing iteration; they such chunks most often occur on tables with primary key “holes”
• Now tested against Django master for cutting edge users and forwards compatibility

0.1.10 (2015-04-30)

• Added the MySQLCache backend for use with Django’s caching framework, a more efficient version of DatabaseCache
• Fix a ZeroDivision error in WeightedAverageRate, which is used in smart iteration

0.1.9 (2015-04-20)

• pt_visual_explain no longer executes the given query before fetching its EXPLAIN
• New pt_fingerprint function that wraps the pt-fingerprint tool efficiently
• For List fields, the new ListF class allows you to do atomic append or pop operations from either end of the list in a single query
• For Set fields, the new SetF class allows you to do atomic add or remove operatiosn from the set in a single query
• The @override_mysql_variables decorator has been introduced which makes testing code with different MySQL configurations easy
• The is_mariadb property gets added onto Django’s MySQL connection class automatically
• A race condition in determining the minimum and maximum primary key values for smart iteration was fixed.

0.1.8 (2015-03-31)

• Add Set and List fields which can store comma-separated sets and lists of a base field with MySQL-specific lookups
• Support MySQL’s GROUP_CONCAT as an aggregate!
• Add a functions module with many MySQL-specific functions for the new Django 1.8 database functions feature
• Allow access of the global and session status for the default connection from a lazy singleton, similar to Django’s connection object
• Fix a different recursion error on count_tries_approx

0.1.7 (2015-03-25)

• Renamed connection_name argument to using on Lock, GlobalStatus, and SessionStatus classes, for more consistency with Django.
• Fix recursion error on QuerySetMixin when using count_tries_approx

0.1.6 (2015-03-21)

• Added support for HANDLER statements as a QuerySet extension
• Now tested on Django 1.8
• Add pk_range argument for ‘smart iteration’ code

0.1.5 (2015-03-11)

• Added manage.py command dbparams for outputting database paramters in formats useful for shell scripts

0.1.4 (2015-03-10)

• Fix release process

0.1.3 (2015-03-08)

• Added pt_visual_explain integration on QuerySet
• Added soundex-based field lookups for the ORM

0.1.2 (2015-03-01)

• Added get_many to GlobalStatus
• Added wait_until_load_low to GlobalStatus which allows you to wait for any high load on your database server to dissipate.
• Added smart iteration classes and methods for QuerySets that allow efficient iteration over very large sets of objects slice-by-slice.

0.1.1 (2015-02-23)

• Added Model and QuerySet subclasses which add the approx_count method

0.1.0 (2015-02-12)

• First release on PyPI
• Locks
• GlobalStatus and SessionStatus