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Fixed #3163 -- Add a "Meta.managed" option to models.

This allows a model to be defined which is not subject to database table
creation and removal. Useful for models that sit over existing tables or
database views.

Thanks to Alexander Myodov, Wolfgang Kriesing and Ryan Kelly for the bulk of
this patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@10008 bcc190cf-cafb-0310-a4f2-bffc1f526a37
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commit b4dd4d4bb7db6533e13be1455ccdc52c3d50cac3 1 parent 98710a5
@malcolmt malcolmt authored
View
1  AUTHORS
@@ -297,6 +297,7 @@ answer newbie questions, and generally made Django that much better:
James Murty
msundstr
Robert Myers <myer0052@gmail.com>
+ Alexander Myodov <alex@myodov.com>
Nebojša Dorđević
Doug Napoleone <doug@dougma.com>
Gopal Narayanan <gopastro@gmail.com>
View
2  django/core/management/commands/syncdb.py
@@ -71,7 +71,7 @@ def handle_noargs(self, **options):
if refto in seen_models:
sql.extend(connection.creation.sql_for_pending_references(refto, self.style, pending_references))
sql.extend(connection.creation.sql_for_pending_references(model, self.style, pending_references))
- if verbosity >= 1:
+ if verbosity >= 1 and sql:
print "Creating table %s" % model._meta.db_table
for statement in sql:
cursor.execute(statement)
View
4 django/db/backends/__init__.py
@@ -450,6 +450,8 @@ def django_table_names(self, only_existing=False):
tables = set()
for app in models.get_apps():
for model in models.get_models(app):
+ if not model._meta.managed:
+ continue
tables.add(model._meta.db_table)
tables.update([f.m2m_db_table() for f in model._meta.local_many_to_many])
if only_existing:
@@ -476,6 +478,8 @@ def sequence_list(self):
for app in apps:
for model in models.get_models(app):
+ if not model._meta.managed:
+ continue
for f in model._meta.local_fields:
if isinstance(f, models.AutoField):
sequence_list.append({'table': model._meta.db_table, 'column': f.column})
View
10 django/db/backends/creation.py
@@ -33,6 +33,8 @@ def sql_create_model(self, model, style, known_models=set()):
from django.db import models
opts = model._meta
+ if not opts.managed:
+ return [], {}
final_output = []
table_output = []
pending_references = {}
@@ -112,6 +114,8 @@ def sql_for_pending_references(self, model, style, pending_references):
"Returns any ALTER TABLE statements to add constraints after the fact."
from django.db.backends.util import truncate_name
+ if not model._meta.managed:
+ return []
qn = self.connection.ops.quote_name
final_output = []
opts = model._meta
@@ -225,6 +229,8 @@ def sql_for_inline_many_to_many_references(self, model, field, style):
def sql_indexes_for_model(self, model, style):
"Returns the CREATE INDEX SQL statements for a single model"
+ if not model._meta.managed:
+ return []
output = []
for f in model._meta.local_fields:
output.extend(self.sql_indexes_for_field(model, f, style))
@@ -255,6 +261,8 @@ def sql_indexes_for_field(self, model, f, style):
def sql_destroy_model(self, model, references_to_delete, style):
"Return the DROP TABLE and restraint dropping statements for a single model"
+ if not model._meta.managed:
+ return []
# Drop the table now
qn = self.connection.ops.quote_name
output = ['%s %s;' % (style.SQL_KEYWORD('DROP TABLE'),
@@ -271,6 +279,8 @@ def sql_destroy_model(self, model, references_to_delete, style):
def sql_remove_table_constraints(self, model, references_to_delete, style):
from django.db.backends.util import truncate_name
+ if not model._meta.managed:
+ return []
output = []
qn = self.connection.ops.quote_name
for rel_class, f in references_to_delete[model]:
View
3  django/db/models/options.py
@@ -21,7 +21,7 @@
DEFAULT_NAMES = ('verbose_name', 'db_table', 'ordering',
'unique_together', 'permissions', 'get_latest_by',
'order_with_respect_to', 'app_label', 'db_tablespace',
- 'abstract')
+ 'abstract', 'managed')
class Options(object):
def __init__(self, meta, app_label=None):
@@ -42,6 +42,7 @@ def __init__(self, meta, app_label=None):
self.pk = None
self.has_auto_field, self.auto_field = False, None
self.abstract = False
+ self.managed = True
self.parents = SortedDict()
self.duplicate_targets = {}
# Managers that have been inherited from abstract base classes. These
View
4 docs/ref/django-admin.txt
@@ -431,6 +431,8 @@ Currently supported:
* ``django`` for all ``*.py`` and ``*.html`` files (default)
* ``djangojs`` for ``*.js`` files
+.. _django-admin-reset:
+
reset <appname appname ...>
---------------------------
@@ -634,6 +636,8 @@ This command is disabled when the ``--settings`` option to
situations, either omit the ``--settings`` option or unset
``DJANGO_SETTINGS_MODULE``.
+.. _django-admin-syncdb:
+
syncdb
------
View
25 docs/ref/models/options.txt
@@ -75,6 +75,30 @@ Example::
See the docs for :meth:`~django.db.models.QuerySet.latest` for more.
+``managed``
+-----------------------
+
+.. attribute:: Options.managed
+
+.. versionadded:: 1.1
+
+If ``False``, no database table creation or deletion operations will be
+performed for this model. This is useful if the model represents an existing
+table or a database view that has been created by some other means.
+
+The default value is ``True``, meaning Django will create the appropriate
+database tables in :ref:`django-admin-syncdb` and remove them as part of a
+:ref:`reset <django-admin-reset>` management command.
+
+If a model contains a :class:`~django.db.models.ManyToManyField` and has
+``managed=False``, the intermediate table for the many-to-many join will also
+not be created. Should you require the intermediate table to be created, set
+it up as an explicit model and use the :attr:`ManyToManyField.through`
+attribute.
+
+For tests involving models with ``managed=False``, it's up to you to ensure
+the correct tables are created as part of the test setup.
+
``order_with_respect_to``
-------------------------
@@ -181,3 +205,4 @@ The plural name for the object::
verbose_name_plural = "stories"
If this isn't given, Django will use :attr:`~Options.verbose_name` + ``"s"``.
+
View
2  tests/modeltests/unmanaged_models/__init__.py
@@ -0,0 +1,2 @@
+
+
View
117 tests/modeltests/unmanaged_models/models.py
@@ -0,0 +1,117 @@
+"""
+Models can have a ``managed`` attribute, which specifies whether the SQL code
+is generated for the table on various manage.py operations.
+"""
+
+from django.db import models
+
+# All of these models are creatd in the database by Django.
+
+class A01(models.Model):
+ f_a = models.CharField(max_length=10, db_index=True)
+ f_b = models.IntegerField()
+
+ class Meta:
+ db_table = 'A01'
+
+ def __unicode__(self):
+ return self.f_a
+
+class B01(models.Model):
+ fk_a = models.ForeignKey(A01)
+ f_a = models.CharField(max_length=10, db_index=True)
+ f_b = models.IntegerField()
+
+ class Meta:
+ db_table = 'B01'
+ # 'managed' is True by default. This tests we can set it explicitly.
+ managed = True
+
+ def __unicode__(self):
+ return self.f_a
+
+class C01(models.Model):
+ mm_a = models.ManyToManyField(A01, db_table='D01')
+ f_a = models.CharField(max_length=10, db_index=True)
+ f_b = models.IntegerField()
+
+ class Meta:
+ db_table = 'C01'
+
+ def __unicode__(self):
+ return self.f_a
+
+# All of these models use the same tables as the previous set (they are shadows
+# of possibly a subset of the columns). There should be no creation errors,
+# since we have told Django they aren't managed by Django.
+
+class A02(models.Model):
+ f_a = models.CharField(max_length=10, db_index=True)
+
+ class Meta:
+ db_table = 'A01'
+ managed = False
+
+ def __unicode__(self):
+ return self.f_a
+
+class B02(models.Model):
+ class Meta:
+ db_table = 'B01'
+ managed = False
+
+ fk_a = models.ForeignKey(A02)
+ f_a = models.CharField(max_length=10, db_index=True)
+ f_b = models.IntegerField()
+
+ def __unicode__(self):
+ return self.f_a
+
+# To re-use the many-to-many intermediate table, we need to manually set up
+# things up.
+class C02(models.Model):
+ mm_a = models.ManyToManyField(A02, through="Intermediate")
+ f_a = models.CharField(max_length=10, db_index=True)
+ f_b = models.IntegerField()
+
+ class Meta:
+ db_table = 'C01'
+ managed = False
+
+ def __unicode__(self):
+ return self.f_a
+
+class Intermediate(models.Model):
+ a02 = models.ForeignKey(A02, db_column="a01_id")
+ c02 = models.ForeignKey(C02, db_column="c01_id")
+
+ class Meta:
+ db_table = 'D01'
+ managed = False
+
+__test__ = {'API_TESTS':"""
+The main test here is that the all the models can be created without any
+database errors. We can also do some more simple insertion and lookup tests
+whilst we're here to show that the second of models do refer to the tables from
+the first set.
+
+# Insert some data into one set of models.
+>>> a = A01.objects.create(f_a="foo", f_b=42)
+>>> _ = B01.objects.create(fk_a=a, f_a="fred", f_b=1729)
+>>> c = C01.objects.create(f_a="barney", f_b=1)
+>>> c.mm_a = [a]
+
+# ... and pull it out via the other set.
+>>> A02.objects.all()
+[<A02: foo>]
+>>> b = B02.objects.all()[0]
+>>> b
+<B02: fred>
+>>> b.fk_a
+<A02: foo>
+>>> C02.objects.filter(f_a=None)
+[]
+>>> C02.objects.filter(mm_a=a.id)
+[<C02: barney>]
+
+"""}
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