66 lines
2.3 KiB
Python
66 lines
2.3 KiB
Python
import logging
|
|
|
|
from django.db import migrations
|
|
from django.apps import apps
|
|
|
|
|
|
class CreateView(migrations.CreateModel):
|
|
|
|
def database_forwards(self, app_label, schema_editor, from_state, to_state):
|
|
fake_model = to_state.apps.get_model(app_label, self.name)
|
|
|
|
if not self.allow_migrate_model(
|
|
schema_editor.connection.alias, fake_model):
|
|
raise
|
|
|
|
model = self._get_model(fake_model, app_label, to_state)
|
|
|
|
self._drop_view(fake_model, schema_editor)
|
|
|
|
if hasattr(model, 'view'):
|
|
self._create_standard_view(model, schema_editor)
|
|
elif hasattr(model, 'get_view_str'):
|
|
self._create_view_from_raw_sql(model.get_view_str(), schema_editor)
|
|
else:
|
|
raise Exception('{} has neither view nor get_view_str'.format(
|
|
model))
|
|
|
|
def database_backwards(self, app_label, schema_editor, from_state, to):
|
|
fake_model = from_state.apps.get_model(app_label, self.name)
|
|
self._drop_view(fake_model, schema_editor)
|
|
|
|
def _get_model(self, state, app_label, fake_model):
|
|
models = apps.get_app_config(app_label).models_module
|
|
|
|
if hasattr(models, self.name):
|
|
return getattr(models, self.name)
|
|
|
|
# TODO: identify model more reliably and support more than 1 level
|
|
for submodule in models.__dict__.values():
|
|
if hasattr(submodule, self.name):
|
|
return getattr(submodule, self.name)
|
|
|
|
logging.warning('Using fake model, this may fail with inherited views')
|
|
return fake_model
|
|
|
|
def _drop_view(self, model, schema_editor):
|
|
sql_template = 'DROP VIEW IF EXISTS %(table)s CASCADE'
|
|
args = {
|
|
'table': schema_editor.quote_name(model._meta.db_table),
|
|
}
|
|
sql = sql_template % args
|
|
schema_editor.execute(sql, None)
|
|
|
|
def _create_standard_view(self, model, schema_editor):
|
|
sql_template = 'CREATE VIEW %(table)s AS %(definition)s'
|
|
qs = str(model.view())
|
|
args = {
|
|
'table': schema_editor.quote_name(model._meta.db_table),
|
|
'definition': qs,
|
|
}
|
|
sql = sql_template % args
|
|
self._create_view_from_raw_sql(sql, schema_editor)
|
|
|
|
def _create_view_from_raw_sql(self, sql, schema_editor):
|
|
schema_editor.execute(sql, None)
|