Commit 729e0b08 authored by Simon Charette's avatar Simon Charette
Browse files

Fixed #24109 -- Allowed RunSQL and RunPython operations to be elided. 

Thanks to Markus Holtermann and Tim Graham for their review.
parent 49f4c9f4

django/db/migrations/operations/base.py

+7 −0
Original line number Diff line number Diff line
@@ -30,6 +30,9 @@ class Operation(object): 
    # DDL transaction support (i.e., does it have no DDL, like RunPython)

    atomic = False



    # Should this operation be considered safe to elide and optimize across?

    elidable = False



    serialization_expand_args = []



    def __new__(cls, *args, **kwargs):
@@ -117,6 +120,10 @@ class Operation(object): 
        replaced with or a boolean that indicates whether or not the specified

        operation can be optimized across.

        """

        if self.elidable:

            return [operation]

        elif operation.elidable:

            return [self]

        return False



    def __repr__(self):

django/db/migrations/operations/fields.py

+10 −2
Original line number Diff line number Diff line
@@ -27,7 +27,10 @@ class FieldOperation(Operation): 
        return self.is_same_model_operation(operation) and self.name_lower == operation.name_lower



    def reduce(self, operation, in_between, app_label=None):

        return not operation.references_field(self.model_name, self.name, app_label)

        return (

            super(FieldOperation, self).reduce(operation, in_between, app_label=app_label) or

            not operation.references_field(self.model_name, self.name, app_label)

        )





class AddField(FieldOperation):
@@ -333,4 +336,9 @@ class RenameField(FieldOperation): 
                    operation.new_name,

                ),

            ]

        return not operation.references_field(self.model_name, self.new_name, app_label)
 
        # Skip `FieldOperation.reduce` as we want to run `references_field`

        # against self.new_name.

        return (

            super(FieldOperation, self).reduce(operation, in_between, app_label=app_label) or

            not operation.references_field(self.model_name, self.new_name, app_label)

        )

django/db/migrations/operations/models.py

+10 −2
Original line number Diff line number Diff line
@@ -21,7 +21,10 @@ class ModelOperation(Operation): 
        return self.name.lower()



    def reduce(self, operation, in_between, app_label=None):

        return not operation.references_model(self.name, app_label)

        return (

            super(ModelOperation, self).reduce(operation, in_between, app_label=app_label) or

            not operation.references_model(self.name, app_label)

        )





class CreateModel(ModelOperation):
@@ -365,7 +368,12 @@ class RenameModel(ModelOperation): 
                    operation.new_name,

                ),

            ]

        return not operation.references_model(self.new_name, app_label)

        # Skip `ModelOperation.reduce` as we want to run `references_model`

        # against self.new_name.

        return (

            super(ModelOperation, self).reduce(operation, in_between, app_label=app_label) or

            not operation.references_model(self.new_name, app_label)

        )





class AlterModelTable(ModelOperation):

django/db/migrations/operations/special.py

+4 −2
Original line number Diff line number Diff line
@@ -71,11 +71,12 @@ class RunSQL(Operation): 
    """

    noop = ''



    def __init__(self, sql, reverse_sql=None, state_operations=None, hints=None):

    def __init__(self, sql, reverse_sql=None, state_operations=None, hints=None, elidable=False):

        self.sql = sql

        self.reverse_sql = reverse_sql

        self.state_operations = state_operations or []

        self.hints = hints or {}

        self.elidable = elidable



    def deconstruct(self):

        kwargs = {
@@ -138,7 +139,7 @@ class RunPython(Operation): 


    reduces_to_sql = False



    def __init__(self, code, reverse_code=None, atomic=True, hints=None):

    def __init__(self, code, reverse_code=None, atomic=True, hints=None, elidable=False):

        self.atomic = atomic

        # Forwards code

        if not callable(code):
@@ -152,6 +153,7 @@ class RunPython(Operation): 
                raise ValueError("RunPython must be supplied with callable arguments")

            self.reverse_code = reverse_code

        self.hints = hints or {}

        self.elidable = elidable



    def deconstruct(self):

        kwargs = {

docs/ref/migration-operations.txt

+16 −2
Original line number Diff line number Diff line
@@ -196,7 +196,7 @@ Special Operations 
RunSQL

------



.. class:: RunSQL(sql, reverse_sql=None, state_operations=None, hints=None)

.. class:: RunSQL(sql, reverse_sql=None, state_operations=None, hints=None, elidable=False)



Allows running of arbitrary SQL on the database - useful for more advanced

features of database backends that Django doesn't support directly, like
@@ -249,6 +249,9 @@ The optional ``hints`` argument will be passed as ``**hints`` to the 
routing decisions. See :ref:`topics-db-multi-db-hints` for more details on

database hints.



The optional ``elidable`` argument determines whether or not the operation will

be removed (elided) when :ref:`squashing migrations <migration-squashing>`.



.. attribute:: RunSQL.noop



    Pass the ``RunSQL.noop`` attribute to ``sql`` or ``reverse_sql`` when you
@@ -257,10 +260,14 @@ database hints. 


.. _sqlparse: https://pypi.python.org/pypi/sqlparse



.. versionadded:: 1.10



    The ``elidable`` argument was added.



RunPython

---------



.. class:: RunPython(code, reverse_code=None, atomic=True, hints=None)

.. class:: RunPython(code, reverse_code=None, atomic=True, hints=None, elidable=False)



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
@@ -278,6 +285,9 @@ The optional ``hints`` argument will be passed as ``**hints`` to the 
routing decision. See :ref:`topics-db-multi-db-hints` for more details on

database hints.



The optional ``elidable`` argument determines whether or not the operation will

be removed (elided) when :ref:`squashing migrations <migration-squashing>`.



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``
@@ -366,6 +376,10 @@ attribute. 
    you want the operation not to do anything in the given direction. This is

    especially useful in making the operation reversible.



.. versionadded:: 1.10



    The ``elidable`` argument was added.



SeparateDatabaseAndState

------------------------