इस प्रक्रिया को मैंने वर्तमान में सुलझा लिया है क्योंकि मैं कुछ समय बाद यहां आया हूं और इसे औपचारिक रूप देने का फैसला किया है।
यह मूल रूप से Potr Czachur के उत्तर
और मैट ब्रायनकॉन के उत्तर पर बनाया गया था
, जिसमें दक्षिण 0.8.4 का उपयोग किया गया था
चरण 1. डिस्कवर बच्चे विदेशी कुंजी रिश्ते
# Caution: This finds OneToOneField and ForeignKey.
# I don't know if this finds all the ways of specifying ManyToManyField.
# Hopefully Django or South throw errors if you have a situation like that.
>>> Cat._meta.get_all_related_objects()
[<RelatedObject: common:toy related to cat>,
<RelatedObject: identity:microchip related to cat>]
तो इस विस्तारित मामले में, हमने एक और संबंधित मॉडल की खोज की है:
# Inside the "identity" app...
class Microchip(models.Model):
# In reality we'd probably want a ForeignKey, but to show the OneToOneField
identifies = models.OneToOneField(Cat)
...
चरण 2. माइग्रेशन बनाएं
# Create the "new"-ly renamed model
# Yes I'm changing the model name in my refactoring too.
python manage.py schemamigration specific create_kittycat --auto
# Drop the old model
python manage.py schemamigration common drop_cat --auto
# Update downstream apps, so South thinks their ForeignKey(s) are correct.
# Can skip models like Toy if the app is already covered
python manage.py schemamigration identity update_microchip_fk --auto
चरण 3. स्रोत नियंत्रण: अब तक किए गए परिवर्तनों को कमिट करें।
यदि आप अपडेट किए गए एप्लिकेशन पर माइग्रेशन लिखने वाली टीम के साथी की तरह मर्ज में चले जाते हैं, तो यह एक अधिक दोहराव वाली प्रक्रिया बनाता है।
चरण 4. माइग्रेशन के बीच निर्भरता जोड़ें।
मूल रूप create_kittycatसे सब कुछ की वर्तमान स्थिति पर निर्भर करता है, और फिर सब कुछ निर्भर करता है create_kittycat।
# create_kittycat
class Migration(SchemaMigration):
depends_on = (
# Original model location
('common', 'the_one_before_drop_cat'),
# Foreign keys to models not in original location
('identity', 'the_one_before_update_microchip_fk'),
)
...
# drop_cat
class Migration(SchemaMigration):
depends_on = (
('specific', 'create_kittycat'),
)
...
# update_microchip_fk
class Migration(SchemaMigration):
depends_on = (
('specific', 'create_kittycat'),
)
...
चरण 5. तालिका का नाम बदलना जिसे हम बनाना चाहते हैं।
# create_kittycat
class Migration(SchemaMigration):
...
# Hopefully for create_kittycat you only need to change the following
# 4 strings to go forward cleanly... backwards will need a bit more work.
old_app = 'common'
old_model = 'cat'
new_app = 'specific'
new_model = 'kittycat'
# You may also wish to update the ContentType.name,
# personally, I don't know what its for and
# haven't seen any side effects from skipping it.
def forwards(self, orm):
db.rename_table(
'%s_%s' % (self.old_app, self.old_model),
'%s_%s' % (self.new_app, self.new_model),
)
if not db.dry_run:
# For permissions, GenericForeignKeys, etc to work properly after migrating.
orm['contenttypes.contenttype'].objects.filter(
app_label=self.old_app,
model=self.old_model,
).update(
app_label=self.new_app,
model=self.new_model,
)
# Going forwards, should be no problem just updating child foreign keys
# with the --auto in the other new South migrations
def backwards(self, orm):
db.rename_table(
'%s_%s' % (self.new_app, self.new_model),
'%s_%s' % (self.old_app, self.old_model),
)
if not db.dry_run:
# For permissions, GenericForeignKeys, etc to work properly after migrating.
orm['contenttypes.contenttype'].objects.filter(
app_label=self.new_app,
model=self.new_model,
).update(
app_label=self.old_app,
model=self.old_model,
)
# Going backwards, you probably should copy the ForeignKey
# db.alter_column() changes from the other new migrations in here
# so they run in the correct order.
#
# Test it! See Step 6 for more details if you need to go backwards.
db.alter_column('common_toy', 'belongs_to_id', self.gf('django.db.models.fields.related.ForeignKey')(to=orm['common.Cat']))
db.alter_column('identity_microchip', 'identifies_id', self.gf('django.db.models.fields.related.OneToOneField')(to=orm['common.Cat']))
# drop_cat
class Migration(SchemaMigration):
...
def forwards(self, orm):
# Remove the db.delete_table(), if you don't at Step 7 you'll likely get
# "django.db.utils.ProgrammingError: table "common_cat" does not exist"
# Leave existing db.alter_column() statements here
db.alter_column('common_toy', 'belongs_to_id', self.gf('django.db.models.fields.related.ForeignKey')(to=orm['specific.KittyCat']))
def backwards(self, orm):
# Copy/paste the auto-generated db.alter_column()
# into the create_kittycat migration if you need backwards to work.
pass
# update_microchip_fk
class Migration(SchemaMigration):
...
def forwards(self, orm):
# Leave existing db.alter_column() statements here
db.alter_column('identity_microchip', 'identifies_id', self.gf('django.db.models.fields.related.OneToOneField')(to=orm['specific.KittyCat']))
def backwards(self, orm):
# Copy/paste the auto-generated db.alter_column()
# into the create_kittycat migration if you need backwards to work.
pass
चरण 6. यदि आपको पीछे की ओर () काम करने और पीछे की ओर चलने वाला KeyError प्राप्त करने की आवश्यकता है।
# the_one_before_create_kittycat
class Migration(SchemaMigration):
# You many also need to add more models to South's FakeORM if you run into
# more KeyErrors, the trade-off chosen was to make going forward as easy as
# possible, as that's what you'll probably want to do once in QA and once in
# production, rather than running the following many times:
#
# python manage.py migrate specific <the_one_before_create_kittycat>
models = {
...
# Copied from 'identity' app, 'update_microchip_fk' migration
u'identity.microchip': {
'Meta': {'object_name': 'Microchip'},
u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
'name': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '80'}),
'identifies': ('django.db.models.fields.related.OneToOneField', [], {to=orm['specific.KittyCat']})
},
...
}
चरण 7. इसका परीक्षण करें - मेरे लिए जो काम करता है वह आपके वास्तविक जीवन की स्थिति के लिए पर्याप्त नहीं हो सकता है :)
python manage.py migrate
# If you need backwards to work
python manage.py migrate specific <the_one_before_create_kittycat>