django1/django/db/migrations/operations/models.py

249 lines
9.3 KiB
Python

from django.db import models, router
from django.db.models.options import normalize_unique_together
from django.db.migrations.state import ModelState
from django.db.migrations.operations.base import Operation
from django.utils import six
class CreateModel(Operation):
"""
Create a model's table.
"""
serialization_expand_args = ['fields', 'options']
def __init__(self, name, fields, options=None, bases=None):
self.name = name
self.fields = fields
self.options = options or {}
self.bases = bases or (models.Model,)
def state_forwards(self, app_label, state):
state.models[app_label, self.name.lower()] = ModelState(app_label, self.name, self.fields, self.options, self.bases)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
apps = to_state.render()
model = apps.get_model(app_label, self.name)
if router.allow_migrate(schema_editor.connection.alias, model):
schema_editor.create_model(model)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
apps = from_state.render()
model = apps.get_model(app_label, self.name)
if router.allow_migrate(schema_editor.connection.alias, model):
schema_editor.delete_model(model)
def describe(self):
return "Create model %s" % (self.name, )
def references_model(self, name, app_label=None):
strings_to_check = [self.name]
# Check we didn't inherit from the model
for base in self.bases:
if isinstance(base, six.string_types):
strings_to_check.append(base.split(".")[-1])
# Check we have no FKs/M2Ms with it
for fname, field in self.fields:
if field.rel:
if isinstance(field.rel.to, six.string_types):
strings_to_check.append(field.rel.to.split(".")[-1])
# Now go over all the strings and compare them
for string in strings_to_check:
if string.lower() == name.lower():
return True
return False
def __eq__(self, other):
return (
(self.__class__ == other.__class__) and
(self.name == other.name) and
(self.options == other.options) and
(self.bases == other.bases) and
([(k, f.deconstruct()[1:]) for k, f in self.fields] == [(k, f.deconstruct()[1:]) for k, f in other.fields])
)
class DeleteModel(Operation):
"""
Drops a model's table.
"""
def __init__(self, name):
self.name = name
def state_forwards(self, app_label, state):
del state.models[app_label, self.name.lower()]
def database_forwards(self, app_label, schema_editor, from_state, to_state):
apps = from_state.render()
model = apps.get_model(app_label, self.name)
if router.allow_migrate(schema_editor.connection.alias, model):
schema_editor.delete_model(model)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
apps = to_state.render()
model = apps.get_model(app_label, self.name)
if router.allow_migrate(schema_editor.connection.alias, model):
schema_editor.create_model(model)
def references_model(self, name, app_label=None):
return name.lower() == self.name.lower()
def describe(self):
return "Delete model %s" % (self.name, )
class RenameModel(Operation):
"""
Renames a model.
"""
def __init__(self, old_name, new_name):
self.old_name = old_name
self.new_name = new_name
def state_forwards(self, app_label, state):
state.models[app_label, self.new_name.lower()] = state.models[app_label, self.old_name.lower()]
state.models[app_label, self.new_name.lower()].name = self.new_name
del state.models[app_label, self.old_name.lower()]
def database_forwards(self, app_label, schema_editor, from_state, to_state):
old_apps = from_state.render()
new_apps = to_state.render()
old_model = old_apps.get_model(app_label, self.old_name)
new_model = new_apps.get_model(app_label, self.new_name)
if router.allow_migrate(schema_editor.connection.alias, new_model):
schema_editor.alter_db_table(
new_model,
old_model._meta.db_table,
new_model._meta.db_table,
)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
old_apps = from_state.render()
new_apps = to_state.render()
old_model = old_apps.get_model(app_label, self.new_name)
new_model = new_apps.get_model(app_label, self.old_name)
if router.allow_migrate(schema_editor.connection.alias, new_model):
schema_editor.alter_db_table(
new_model,
old_model._meta.db_table,
new_model._meta.db_table,
)
def references_model(self, name, app_label=None):
return (
name.lower() == self.old_name.lower() or
name.lower() == self.new_name.lower()
)
def describe(self):
return "Rename model %s to %s" % (self.old_name, self.new_name)
class AlterModelTable(Operation):
"""
Renames a model's table
"""
def __init__(self, name, table):
self.name = name
self.table = table
def state_forwards(self, app_label, state):
state.models[app_label, self.name.lower()].options["db_table"] = self.table
def database_forwards(self, app_label, schema_editor, from_state, to_state):
old_apps = from_state.render()
new_apps = to_state.render()
old_model = old_apps.get_model(app_label, self.name)
new_model = new_apps.get_model(app_label, self.name)
if router.allow_migrate(schema_editor.connection.alias, new_model):
schema_editor.alter_db_table(
new_model,
old_model._meta.db_table,
new_model._meta.db_table,
)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
return self.database_forwards(app_label, schema_editor, from_state, to_state)
def references_model(self, name, app_label=None):
return name.lower() == self.name.lower()
def describe(self):
return "Rename table for %s to %s" % (self.name, self.table)
class AlterUniqueTogether(Operation):
"""
Changes the value of index_together to the target one.
Input value of unique_together must be a set of tuples.
"""
def __init__(self, name, unique_together):
self.name = name
unique_together = normalize_unique_together(unique_together)
self.unique_together = set(tuple(cons) for cons in unique_together)
def state_forwards(self, app_label, state):
model_state = state.models[app_label, self.name.lower()]
model_state.options["unique_together"] = self.unique_together
def database_forwards(self, app_label, schema_editor, from_state, to_state):
old_apps = from_state.render()
new_apps = to_state.render()
old_model = old_apps.get_model(app_label, self.name)
new_model = new_apps.get_model(app_label, self.name)
if router.allow_migrate(schema_editor.connection.alias, new_model):
schema_editor.alter_unique_together(
new_model,
getattr(old_model._meta, "unique_together", set()),
getattr(new_model._meta, "unique_together", set()),
)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
return self.database_forwards(app_label, schema_editor, from_state, to_state)
def references_model(self, name, app_label=None):
return name.lower() == self.name.lower()
def describe(self):
return "Alter unique_together for %s (%s constraints)" % (self.name, len(self.unique_together))
class AlterIndexTogether(Operation):
"""
Changes the value of index_together to the target one.
Input value of index_together must be a set of tuples.
"""
def __init__(self, name, index_together):
self.name = name
self.index_together = set(tuple(cons) for cons in index_together)
def state_forwards(self, app_label, state):
model_state = state.models[app_label, self.name.lower()]
model_state.options["index_together"] = self.index_together
def database_forwards(self, app_label, schema_editor, from_state, to_state):
old_apps = from_state.render()
new_apps = to_state.render()
old_model = old_apps.get_model(app_label, self.name)
new_model = new_apps.get_model(app_label, self.name)
if router.allow_migrate(schema_editor.connection.alias, new_model):
schema_editor.alter_index_together(
new_model,
getattr(old_model._meta, "index_together", set()),
getattr(new_model._meta, "index_together", set()),
)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
return self.database_forwards(app_label, schema_editor, from_state, to_state)
def references_model(self, name, app_label=None):
return name.lower() == self.name.lower()
def describe(self):
return "Alter index_together for %s (%s constraints)" % (self.name, len(self.index_together))