Improved formatting and links of migration docs.

docs/ref/migration-operations.txt

@@ -2,39 +2,39 @@
 Migration Operations
 ====================
 
-Migration files are composed of one or more Operations, objects that
+.. module:: django.db.migrations.operations
+
+Migration files are composed of one or more ``Operation``\s, objects that
 declaratively record what the migration should do to your database.
 
-Django also uses these Operation objects to work out what your models
+Django also uses these ``Operation`` objects to work out what your models
 looked like historically, and to calculate what changes you've made to
 your models since the last migration so it can automatically write
 your migrations; that's why they're declarative, as it means Django can
 easily load them all into memory and run through them without touching
 the database to work out what your project should look like.
 
-There are also more specialized Operation objects which are for things like
+There are also more specialized ``Operation`` objects which are for things like
 :ref:`data migrations <data-migrations>` and for advanced manual database
-manipulation. You can also write your own Operation classes if you want
+manipulation. You can also write your own ``Operation`` classes if you want
 to encapsulate a custom change you commonly make.
 
-If you need an empty migration file to write your own Operation objects
+If you need an empty migration file to write your own ``Operation`` objects
 into, just use ``python manage.py makemigrations --empty yourappname``,
 but be aware that manually adding schema-altering operations can confuse the
-migration autodetector and make resulting runs of ``makemigrations`` output
-incorrect code.
+migration autodetector and make resulting runs of :djadmin:`makemigrations`
+output incorrect code.
 
 All of the core Django operations are available from the
 ``django.db.migrations.operations`` module.
 
-
 Schema Operations
 =================
 
 CreateModel
 -----------
-::
 
-    CreateModel(name, fields, options=None, bases=None)
+.. class:: CreateModel(name, fields, options=None, bases=None)
 
 Creates a new model in the project history and a corresponding table in the
 database to match it.
@@ -53,21 +53,17 @@ it can contain both class objects as well as strings in the format
 from the historical version). If it's not supplied, it defaults to just
 inheriting from the standard ``models.Model``.
 
-
 DeleteModel
 -----------
-::
 
-    DeleteModel(name)
+.. class:: DeleteModel(name)
 
 Deletes the model from the project history and its table from the database.
 
-
 RenameModel
 -----------
-::
 
-    RenameModel(old_name, new_name)
+.. class:: RenameModel(old_name, new_name)
 
 Renames the model from an old name to a new one.
 
@@ -77,41 +73,36 @@ the autodetector, this will look like you deleted a model with the old name
 and added a new one with a different name, and the migration it creates will
 lose any data in the old table.
 
-
 AlterModelTable
 ---------------
-::
 
-    AlterModelTable(name, table)
-
-Changes the model's table name (the ``db_table`` option on the ``Meta`` subclass)
+.. class:: AlterModelTable(name, table)
 
+Changes the model's table name (the :attr:`~django.db.models.Options.db_table`
+option on the ``Meta`` subclass).
 
 AlterUniqueTogether
 -------------------
-::
-
-    AlterUniqueTogether(name, unique_together)
 
-Changes the model's set of unique constraints
-(the ``unique_together`` option on the ``Meta`` subclass)
+.. class:: AlterUniqueTogether(name, unique_together)
 
+Changes the model's set of unique constraints (the
+:attr:`~django.db.models.Options.unique_together` option on the ``Meta``
+subclass).
 
 AlterIndexTogether
 ------------------
-::
-
-    AlterIndexTogether(name, index_together)
 
-Changes the model's set of custom indexes
-(the ``index_together`` option on the ``Meta`` subclass)
+.. class:: AlterIndexTogether(name, index_together)
 
+Changes the model's set of custom indexes (the
+:attr:`~django.db.models.Options.index_together` option on the ``Meta``
+subclass).
 
 AddField
 --------
-::
 
-    AddField(model_name, name, field, preserve_default=True)
+.. class:: AddField(model_name, name, field, preserve_default=True)
 
 Adds a field to a model. ``model_name`` is the model's name, ``name`` is
 the field's name, and ``field`` is an unbound Field instance (the thing
@@ -126,12 +117,10 @@ a default value to put into existing rows. It does not effect the behavior
 of setting defaults in the database directly - Django never sets database
 defaults, and always applies them in the Django ORM code.
 
-
 RemoveField
 -----------
-::
 
-    RemoveField(model_name, name)
+.. class:: RemoveField(model_name, name)
 
 Removes a field from a model.
 
@@ -139,42 +128,34 @@ Bear in mind that when reversed this is actually adding a field to a model;
 if the field is not nullable this may make this operation irreversible (apart
 from any data loss, which of course is irreversible).
 
-
 AlterField
 ----------
-::
 
-    AlterField(model_name, name, field)
+.. class:: AlterField(model_name, name, field)
 
-Alters a field's definition, including changes to its type, ``null``, ``unique``,
-``db_column`` and other field attributes.
+Alters a field's definition, including changes to its type,
+:attr:`~django.db.models.Field.null`, :attr:`~django.db.models.Field.unique`,
+:attr:`~django.db.models.Field.db_column` and other field attributes.
 
 Note that not all changes are possible on all databases - for example, you
 cannot change a text-type field like ``models.TextField()`` into a number-type
 field like ``models.IntegerField()`` on most databases.
 
-
 RenameField
 -----------
-::
-
-    RenameField(model_name, old_name, new_name)
-
-Changes a field's name (and, unless ``db_column`` is set, its column name).
 
+.. class:: RenameField(model_name, old_name, new_name)
 
+Changes a field's name (and, unless :attr:`~django.db.models.Field.db_column`
+is set, its column name).
 
 Special Operations
 ==================
 
-.. _operation-run-sql:
-
 RunSQL
 ------
 
-::
-
-    RunSQL(sql, reverse_sql=None, state_operations=None)
+.. class:: RunSQL(sql, reverse_sql=None, state_operations=None)
 
 Allows running of arbitrary SQL on the database - useful for more advanced
 features of database backends that Django doesn't support directly, like
@@ -194,24 +175,22 @@ operation that adds that field and so will try to run it again).
 
 .. _sqlparse: https://pypi.python.org/pypi/sqlparse
 
-.. _operation-run-python:
-
 RunPython
 ---------
 
-::
-
-    RunPython(code, reverse_code=None)
+.. class:: RunPython(code, reverse_code=None)
 
 Runs custom Python code in a historical context. ``code`` (and ``reverse_code``
 if supplied) should be callable objects that accept two arguments; the first is
 an instance of ``django.apps.registry.Apps`` containing historical models that
 match the operation's place in the project history, and the second is an
-instance of SchemaEditor.
+instance of :class:`SchemaEditor
+<django.db.backends.schema.BaseDatabaseSchemaEditor>`.
 
 You are advised to write the code as a separate function above the ``Migration``
 class in the migration file, and just pass it to ``RunPython``. Here's an
-example of using RunPython to create some initial objects on a Country model::
+example of using ``RunPython`` to create some initial objects on a ``Country``
+model::
 
     # encoding: utf8
     from django.db import models, migrations
@@ -245,19 +224,16 @@ or ``orm["appname", "Model"]`` references from South directly into
 ``apps.get_model("appname", "Model")`` references here and leave most of the
 rest of the code unchanged for data migrations.
 
-Much like ``RunSQL``, ensure that if you change schema inside here you're
+Much like :class:`RunSQL`, ensure that if you change schema inside here you're
 either doing it outside the scope of the Django model system (e.g. triggers)
-or that you use ``SeparateDatabaseAndState`` to add in operations that will
+or that you use :class:`SeparateDatabaseAndState` to add in operations that will
 reflect your changes to the model state - otherwise, the versioned ORM and
 the autodetector will stop working correctly.
 
-
 SeparateDatabaseAndState
 ------------------------
 
-::
-
-    SeparateDatabaseAndState(database_operations=None, state_operations=None)
+.. class:: SeparateDatabaseAndState(database_operations=None, state_operations=None)
 
 A highly specialized operation that let you mix and match the database
 (schema-changing) and state (autodetector-powering) aspects of operations.
@@ -266,13 +242,12 @@ It accepts two list of operations, and when asked to apply state will use the
 state list, and when asked to apply changes to the database will use the database
 list. Do not use this operation unless you're very sure you know what you're doing.
 
-
 Writing your own
 ================
 
 Operations have a relatively simple API, and they're designed so that you can
 easily write your own to supplement the built-in Django ones. The basic structure
-of an Operation looks like this::
+of an ``Operation`` looks like this::
 
     from django.db.migrations.operations.base import Operation
 
@@ -317,7 +292,7 @@ historical models.
 
 Some things to note:
 
-* You don't need to learn too much about ProjectState to just write simple
+* You don't need to learn too much about ``ProjectState`` to just write simple
   migrations; just know that it has a ``.render()`` method that turns it into
   an app registry (which you can then call ``get_model`` on).
 

docs/ref/schema-editor.txt

@@ -1,6 +1,10 @@
-============
-SchemaEditor
-============
+================
+``SchemaEditor``
+================
+
+.. module:: django.db.backends.schema
+
+.. class:: BaseDatabaseSchemaEditor
 
 Django's migration system is split into two parts; the logic for calculating
 and storing what operations should be run (``django.db.migrations``), and the
@@ -27,10 +31,10 @@ of change are not possible on all databases - for example, MyISAM does not
 support foreign key constraints.
 
 If you are writing or maintaining a third-party database backend for Django,
-you will need to provide a SchemaEditor implementation in order to work with
+you will need to provide a ``SchemaEditor`` implementation in order to work with
 1.7's migration functionality - however, as long as your database is relatively
 standard in its use of SQL and relational design, you should be able to
-subclass one of the built-in Django SchemaEditor classes and just tweak the
+subclass one of the built-in Django ``SchemaEditor`` classes and just tweak the
 syntax a little. Also note that there are a few new database features that
 migrations will look for: ``can_rollback_ddl`` and
 ``supports_combined_alters`` are the most important.
@@ -41,9 +45,7 @@ Methods
 execute
 -------
 
-::
-
-    execute(sql, params=[])
+.. method:: BaseDatabaseSchemaEditor.execute(sql, params=[])
 
 Executes the SQL statement passed in, with parameters if supplied. This
 is a simple wrapper around the normal database cursors that allows
@@ -52,92 +54,71 @@ capture of the SQL to a ``.sql`` file if the user wishes.
 create_model
 ------------
 
-::
-
-    create_model(model)
+.. method:: BaseDatabaseSchemaEditor.create_model(model)
 
 Creates a new table in the database for the provided model, along with any
 unique constraints or indexes it requires.
 
-
 delete_model
 ------------
 
-::
-
-    delete_model(model)
+.. method:: BaseDatabaseSchemaEditor.delete_model(model)
 
 Drops the model's table in the database along with any unique constraints
 or indexes it has.
 
-
 alter_unique_together
 ---------------------
 
-::
-
-    alter_unique_together(model, old_unique_together, new_unique_together)
-
-Changes a model's unique_together value; this will add or remove unique
-constraints from the model's table until they match the new value.
+.. method:: BaseDatabaseSchemaEditor.alter_unique_together(model, old_unique_together, new_unique_together)
 
+Changes a model's :attr:`~django.db.models.Options.unique_together` value; this
+will add or remove unique constraints from the model's table until they match
+the new value.
 
 alter_index_together
 --------------------
 
-::
-
-    alter_index_together(model, old_index_together, new_index_together)
-
-Changes a model's index_together value; this will add or remove indexes
-from the model's table until they match the new value.
+.. method:: BaseDatabaseSchemaEditor.alter_index_together(model, old_index_together, new_index_together)
 
+Changes a model's :attr:`~django.db.models.Options.index_together` value; this
+will add or remove indexes from the model's table until they match the new
+value.
 
 alter_db_table
 --------------
 
-::
-
-    alter_db_table(model, old_db_table, new_db_table)
+.. method:: BaseDatabaseSchemaEditor.alter_db_table(model, old_db_table, new_db_table)
 
 Renames the model's table from ``old_db_table`` to ``new_db_table``.
 
-
 alter_db_tablespace
 -------------------
 
-::
-
-    alter_db_tablespace(model, old_db_tablespace, new_db_tablespace)
+.. method:: BaseDatabaseSchemaEditor.alter_db_tablespace(model, old_db_tablespace, new_db_tablespace)
 
 Moves the model's table from one tablespace to another.
 
-
 add_field
 ---------
 
-::
-
-    add_field(model, field)
+.. method:: BaseDatabaseSchemaEditor.add_field(model, field)
 
 Adds a column (or sometimes multiple) to the model's table to represent the
 field. This will also add indexes or a unique constraint
 if the field has ``db_index=True`` or ``unique=True``.
 
-If the field is a ManyToManyField without a value for ``through``, instead of
-creating a column, it will make a table to represent the relationship. If
+If the field is a ``ManyToManyField`` without a value for ``through``, instead
+of creating a column, it will make a table to represent the relationship. If
 ``through`` is provided, it is a no-op.
 
 If the field is a ``ForeignKey``, this will also add the foreign key
 constraint to the column.
 
-
 remove_field
 ------------
 
-::
-
-    remove_field(model, field)
+.. method:: BaseDatabaseSchemaEditor.remove_field(model, field)
 
 Removes the column(s) representing the field from the model's table, along
 with any unique constraints, foreign key constraints, or indexes caused by
@@ -147,25 +128,22 @@ If the field is a ManyToManyField without a value for ``through``, it will
 remove the table created to track the relationship. If
 ``through`` is provided, it is a no-op.
 
-
 alter_field
 ------------
 
-::
-
-    alter_field(model, old_field, new_field, strict=False)
+.. method:: BaseDatabaseSchemaEditor.alter_field(model, old_field, new_field, strict=False)
 
 This transforms the field on the model from the old field to the new one. This
-includes changing the name of the column (the ``db_column`` attribute),
-changing the type of the field (if the field class changes), changing
-the ``NULL`` status of the field, adding or removing field-only unique
-constraints and indexes, changing primary key, and changing the destination
-of ForeignKey constraints.
+includes changing the name of the column (the
+:attr:`~django.db.models.Field.db_column` attribute), changing the type of the
+field (if the field class changes), changing the ``NULL`` status of the field,
+adding or removing field-only unique constraints and indexes, changing primary
+key, and changing the destination of ``ForeignKey`` constraints.
 
 The most common transformation this cannot do is transforming a
-ManyToManyField into a normal Field or vice-versa; Django cannot do this
-without losing data, and so it will refuse to do it. Instead, ``remove_field``
-and ``add_field`` should be called separately.
+``ManyToManyField`` into a normal Field or vice-versa; Django cannot do this
+without losing data, and so it will refuse to do it. Instead,
+:meth:`.remove_field` and :meth:`.add_field` should be called separately.
 
 If the database has the ``supports_combined_alters``, Django will try and
 do as many of these in a single database call as possible; otherwise, it will

docs/releases/1.7.txt

@@ -639,8 +639,9 @@ Management Commands
 * :ref:`initial-sql` now works better if the sqlparse_ Python library is
   installed.
 
-  Note that it's deprecated in favor of the :ref:`RunSQL <operation-run-sql>`
-  operation of migrations, which benefits from the improved behavior.
+  Note that it's deprecated in favor of the
+  :class:`~django.db.migrations.operations.RunSQL` operation of migrations,
+  which benefits from the improved behavior.
 
 .. _sqlparse: https://pypi.python.org/pypi/sqlparse
 

docs/topics/migrations.txt

@@ -17,7 +17,7 @@ A Brief History
 
 Prior to version 1.7, Django only supported adding new models to the
 database; it was not possible to alter or remove existing models via the
-``syncdb`` command (the predecessor to ``migrate``).
+``syncdb`` command (the predecessor to :djadmin:`migrate`).
 
 Third-party tools, most notably `South <http://south.aeracode.org>`_,
 provided support for these additional types of change, but it was considered
@@ -53,7 +53,8 @@ staging machines, and eventually your production machines.
 
 .. note::
     It is possible to override the name of the package which contains the
-    migrations on a per-app basis by modifying the :setting:`MIGRATION_MODULES` setting.
+    migrations on a per-app basis by modifying the :setting:`MIGRATION_MODULES`
+    setting.
 
 Migrations will run the same way on the same dataset and produce consistent
 results, meaning that what you see in development and staging is, under the
@@ -184,14 +185,14 @@ Dependencies
 While migrations are per-app, the tables and relationships implied by
 your models are too complex to be created for just one app at a time. When
 you make a migration that requires something else to run - for example,
-you add a ForeignKey in your ``books`` app to your ``authors`` app - the
+you add a ``ForeignKey`` in your ``books`` app to your ``authors`` app - the
 resulting migration will contain a dependency on a migration in ``authors``.
 
 This means that when you run the migrations, the ``authors`` migration runs
 first and creates the table the ``ForeignKey`` references, and then the migration
 that makes the ``ForeignKey`` column runs afterwards and creates the constraint.
-If this didn't happen, the migration would try to create the ForeignKey column
-without the table it's referencing existing and your database would
+If this didn't happen, the migration would try to create the ``ForeignKey``
+column without the table it's referencing existing and your database would
 throw an error.
 
 This dependency behavior affects most migration operations where you
@@ -228,8 +229,8 @@ inspects this object for four attributes, only two of which are used
 most of the time:
 
 * ``dependencies``, a list of migrations this one depends on.
-* ``operations``, a list of Operation classes that define what this migration
-  does.
+* ``operations``, a list of ``Operation`` classes that define what this
+  migration does.
 
 The operations are the key; they are a set of declarative instructions which
 tell Django what schema changes need to be made. Django scans them and
@@ -252,9 +253,9 @@ Custom fields
 ~~~~~~~~~~~~~
 
 You can't modify the number of positional arguments in an already migrated
-custom field without raising a TypeError. The old migration will call the
+custom field without raising a ``TypeError``. The old migration will call the
 modified ``__init__`` method with the old signature. So if you need a new
-argument, please create a keyword argument and use e.g.
+argument, please create a keyword argument and add something like
 ``assert kwargs.get('argument_name') is not None`` in the constructor.
 
 Adding migrations to apps
@@ -285,7 +286,6 @@ Note that this only works given two things:
   that your database doesn't match your models, you'll just get errors when
   migrations try to modify those tables.
 
-
 .. _historical-models:
 
 Historical models
@@ -293,9 +293,9 @@ Historical models
 
 When you run migrations, Django is working from historical versions of
 your models stored in the migration files. If you write Python code
-using the ``django.db.migrations.RunPython`` operation, or if you have
-``allow_migrate`` methods on your database routers, you will be exposed
-to these versions of your models.
+using the :class:`~django.db.migrations.operations.RunPython` operation, or if
+you have ``allow_migrate`` methods on your database routers, you will be
+exposed to these versions of your models.
 
 Because it's impossible to serialize arbitrary Python code, these historical
 models will not have any custom methods or managers that you have defined.
@@ -304,9 +304,9 @@ They will, however, have the same fields, relationships and ``Meta`` options
 
 .. warning::
 
-  This means that you will NOT have custom save() methods called on objects
-  when you access them in migrations, and you will NOT have any custom constructors
-  or instance methods. Plan appropriately!
+  This means that you will NOT have custom ``save()`` methods called on objects
+  when you access them in migrations, and you will NOT have any custom
+  constructors or instance methods. Plan appropriately!
 
 In addition, the base classes of the model are just stored as pointers,
 so you must always keep base classes around for as long as there is a migration
@@ -314,7 +314,6 @@ that contains a reference to them. On the plus side, methods and managers
 from these base classes inherit normally, so if you absolutely need access
 to these you can opt to move them into a superclass.
 
-
 .. _data-migrations:
 
 Data Migrations
@@ -330,7 +329,7 @@ Django can't automatically generate data migrations for you, as it does with
 schema migrations, but it's not very hard to write them. Migration files in
 Django are made up of :doc:`Operations </ref/migration-operations>`, and
 the main operation you use for data migrations is
-:ref:`RunPython <operation-run-python>`.
+:class:`~django.db.migrations.operations.RunPython`.
 
 To start, make an empty migration file you can work from (Django will put
 the file in the right place, suggest a name, and add dependencies for you)::
@@ -351,13 +350,15 @@ Then, open up the file; it should look something like this::
         operations = [
         ]
 
-Now, all you need to do is create a new function and have RunPython use it.
-RunPython expects a callable as its argument which takes two arguments - the
-first is an :doc:`app registry </ref/applications/>` that has the historical
-versions of all your models loaded into it to match where in your history the
-migration sits, and the second is a :doc:`SchemaEditor </ref/schema-editor>`,
-which you can use to manually effect database schema changes (but beware,
-doing this can confuse the migration autodetector!)
+Now, all you need to do is create a new function and have
+:class:`~django.db.migrations.operations.RunPython` use it.
+:class:`~django.db.migrations.operations.RunPython` expects a callable as its argument
+which takes two arguments - the first is an :doc:`app registry
+</ref/applications/>` that has the historical versions of all your models
+loaded into it to match where in your history the migration sits, and the
+second is a :doc:`SchemaEditor </ref/schema-editor>`, which you can use to
+manually effect database schema changes (but beware, doing this can confuse
+the migration autodetector!)
 
 Let's write a simple migration that populates our new ``name`` field with the
 combined values of ``first_name`` and ``last_name`` (we've come to our senses
@@ -389,8 +390,8 @@ Once that's done, we can just run ``python manage.py migrate`` as normal and
 the data migration will run in place alongside other migrations.
 
 If you're interested in the more advanced migration operations, or want
-to be able to write your own, see our
-:doc:`migration operations reference </ref/migration-operations>`.
+to be able to write your own, see the :doc:`migration operations reference
+</ref/migration-operations>`.
 
 .. _migration-squashing:
 
@@ -406,15 +407,19 @@ Squashing is the act of reducing an existing set of many migrations down to
 one (or sometimes a few) migrations which still represent the same changes.
 
 Django does this by taking all of your existing migrations, extracting their
-Operations and putting them all in sequence, and then running an optimizer
+``Operation``\s and putting them all in sequence, and then running an optimizer
 over them to try and reduce the length of the list - for example, it knows
-that ``CreateModel`` and ``DeleteModel`` cancel each other out, and it knows
-that ``AddColumn`` can be rolled into ``CreateModel``.
+that :class:`~django.db.migrations.operations.CreateModel` and
+:class:`~django.db.migrations.operations.DeleteModel` cancel each other out,
+and it knows that :class:`~django.db.migrations.operations.AddField` can be
+rolled into :class:`~django.db.migrations.operations.CreateModel`.
 
 Once the operation sequence has been reduced as much as possible - the amount
 possible depends on how closely intertwined your models are and if you have
-any RunSQL or RunPython operations (which can't be optimized through) - Django
-will them write it back out into a new set of initial migration files.
+any :class:`~django.db.migrations.operations.RunSQL`
+or :class:`~django.db.migrations.operations.RunPython` operations (which can't
+be optimized through) - Django will them write it back out into a new set of
+initial migration files.
 
 These files are marked to say they replace the previously-squashed migrations,
 so they can coexist with the old migration files, and Django will intelligently
@@ -452,9 +457,9 @@ work::
 Note that model interdependencies in Django can get very complex, and squashing
 may occasionally result in an optimized migration that doesn't work or is
 impossible to run. When this occurs, you can re-try with ``--no-optimize``, but
-please file a bug report either way detailing the models and their
-relationships so we can improve the optimizer to handle your case.
-
+please `file a bug report <https://code.djangoproject.com/newticket>`_ either
+way detailing the models and their relationships so we can improve the
+optimizer to handle your case.
 
 .. _migration-serializing:
 
@@ -508,7 +513,6 @@ available at the top level of a module it is not serializable.
 Django will write out the value as an instantiation of your class with the
 given arguments, similar to the way it writes out references to Django fields.
 
-
 Upgrading from South
 --------------------
 
@@ -517,9 +521,13 @@ If you already have pre-existing migrations created with
 ``django.db.migrations`` is quite simple:
 
 * Ensure all installs are fully up-to-date with their migrations
-* Delete all your (numbered) migration files, but not the directory or __init__.py - make sure you remove the ``.pyc`` files too.
-* Run ``python manage.py makemigrations``. Django should see the empty migration directories and make new initial migrations in the new format.
-* Run ``python manage.py migrate``. Django will see that the tables for the initial migrations already exist and mark them as applied without running them.
+* Delete all your (numbered) migration files, but not the directory or
+  ``__init__.py`` - make sure you remove the ``.pyc`` files too.
+* Run ``python manage.py makemigrations``. Django should see the empty
+  migration directories and make new initial migrations in the new format.
+* Run ``python manage.py migrate``. Django will see that the tables for the
+  initial migrations already exist and mark them as applied without running
+  them.
 
 That's it! The only complication is if you have a circular dependency loop
 of foreign keys; in this case, ``makemigrations`` might make more than one