Commit c8bac4b5 authored by Markus Holtermann's avatar Markus Holtermann Committed by Tim Graham
Browse files

Fixed #24098 -- Added no-op attributes to RunPython and RunSQL 

Thanks Loïc Bistuer and Tim Graham for the discussion and review.
parent 67d6a8c4

django/db/migrations/operations/special.py

+10 −5
Original line number Diff line number Diff line
@@ -61,6 +61,7 @@ class RunSQL(Operation): 
    Also accepts a list of operations that represent the state change effected

    by this SQL change, in case it's custom column/table creation/deletion.

    """

    noop = ''



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

        self.sql = sql
@@ -100,9 +101,9 @@ class RunSQL(Operation): 
    def describe(self):

        return "Raw SQL operation"



    def _run_sql(self, schema_editor, sql):

        if isinstance(sql, (list, tuple)):

            for sql in sql:

    def _run_sql(self, schema_editor, sqls):

        if isinstance(sqls, (list, tuple)):

            for sql in sqls:

                params = None

                if isinstance(sql, (list, tuple)):

                    elements = len(sql)
@@ -111,8 +112,8 @@ class RunSQL(Operation): 
                    else:

                        raise ValueError("Expected a 2-tuple but got %d" % elements)

                schema_editor.execute(sql, params=params)

        else:

            statements = schema_editor.connection.ops.prepare_sql_script(sql)

        elif sqls != RunSQL.noop:

            statements = schema_editor.connection.ops.prepare_sql_script(sqls)

            for statement in statements:

                schema_editor.execute(statement, params=None)
@@ -175,3 +176,7 @@ class RunPython(Operation): 


    def describe(self):

        return "Raw Python operation"



    @staticmethod

    def noop(apps, schema_editor):

        return None

docs/ref/migration-operations.txt

+16 −0
Original line number Diff line number Diff line
@@ -245,6 +245,14 @@ operation that adds that field and so will try to run it again). 
    The ability to pass parameters to the ``sql`` and ``reverse_sql`` queries

    was added.



.. attribute:: RunSQL.noop



    .. versionadded:: 1.8



    Pass the ``RunSQL.noop`` attribute to ``sql`` or ``reverse_sql`` when you

    want the operation not to do anything in the given direction. This is

    especially useful in making the operation reversible.



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



RunPython
@@ -321,6 +329,14 @@ set ``atomic=False``. 
    ``schema_editor.connection.alias``, where ``schema_editor`` is the second

    argument to your function).



.. staticmethod:: RunPython.noop



    .. versionadded:: 1.8



    Pass the ``RunPython.noop`` method to ``code`` or ``reverse_code`` when

    you want the operation not to do anything in the given direction. This is

    especially useful in making the operation reversible.



SeparateDatabaseAndState

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

docs/releases/1.8.txt

+5 −0
Original line number Diff line number Diff line
@@ -457,6 +457,11 @@ Migrations 
* A :ref:`generic mechanism to handle the deprecation of model fields

  <migrations-removing-model-fields>` was added.



* The :attr:`RunPython.noop <django.db.migrations.operations.RunPython.noop>`

  and :meth:`RunSQL.noop() <django.db.migrations.operations.RunSQL.noop>` class

  attribute/method were added to ease in making ``RunPython`` and ``RunSQL``

  operations reversible.



Models

^^^^^^

tests/migrations/test_migrations_squashed_complex/1_auto.py

+1 −1
Original line number Diff line number Diff line
@@ -7,5 +7,5 @@ from django.db import migrations 
class Migration(migrations.Migration):



    operations = [

        migrations.RunPython(lambda apps, schema_editor: None)

        migrations.RunPython(migrations.RunPython.noop)

    ]

tests/migrations/test_migrations_squashed_complex/2_auto.py

+1 −1
Original line number Diff line number Diff line
@@ -9,5 +9,5 @@ class Migration(migrations.Migration): 
    dependencies = [("migrations", "1_auto")]



    operations = [

        migrations.RunPython(lambda apps, schema_editor: None)

        migrations.RunPython(migrations.RunPython.noop)

    ]