First stab at some migration creation commands

This commit is contained in:
Andrew Godwin 2013-06-19 15:36:22 +01:00
parent 2ae8a8a77d
commit ab5cbae9b7
10 changed files with 210 additions and 52 deletions

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@ -0,0 +1,52 @@
import sys
from optparse import make_option
from django.core.management.base import BaseCommand
from django.core.management.color import color_style
from django.core.exceptions import ImproperlyConfigured
from django.db import connections
from django.db.migrations.loader import MigrationLoader
from django.db.migrations.autodetector import MigrationAutodetector, InteractiveMigrationQuestioner
from django.db.migrations.state import ProjectState
from django.db.models.loading import cache
class Command(BaseCommand):
option_list = BaseCommand.option_list + (
make_option('--empty', action='store_true', dest='empty', default=False,
help='Make a blank migration.'),
)
help = "Creates new migration(s) for apps."
usage_str = "Usage: ./manage.py createmigration [--empty] [app [app ...]]"
def handle(self, *app_labels, **options):
self.verbosity = int(options.get('verbosity'))
self.interactive = options.get('interactive')
self.style = color_style()
# Make sure the app they asked for exists
app_labels = set(app_labels)
for app_label in app_labels:
try:
cache.get_app(app_label)
except ImproperlyConfigured:
self.stderr.write("The app you specified - '%s' - could not be found. Is it in INSTALLED_APPS?" % app_label)
sys.exit(2)
# Load the current graph state
loader = MigrationLoader(connections["default"])
# Detect changes
autodetector = MigrationAutodetector(
loader.graph.project_state(),
ProjectState.from_app_cache(cache),
InteractiveMigrationQuestioner(specified_apps=app_labels),
)
changes = autodetector.changes()
changes = autodetector.arrange_for_graph(changes, loader.graph)
if app_labels:
changes = autodetector.trim_to_apps(changes, app_labels)
print changes

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@ -5,7 +5,7 @@ import traceback
from django.conf import settings from django.conf import settings
from django.core.management import call_command from django.core.management import call_command
from django.core.management.base import NoArgsCommand from django.core.management.base import NoArgsCommand
from django.core.management.color import color_style from django.core.management.color import color_style, no_style
from django.core.management.sql import custom_sql_for_model, emit_post_sync_signal, emit_pre_sync_signal from django.core.management.sql import custom_sql_for_model, emit_post_sync_signal, emit_pre_sync_signal
from django.db import connections, router, transaction, models, DEFAULT_DB_ALIAS from django.db import connections, router, transaction, models, DEFAULT_DB_ALIAS
from django.db.migrations.executor import MigrationExecutor from django.db.migrations.executor import MigrationExecutor
@ -32,6 +32,7 @@ class Command(NoArgsCommand):
self.interactive = options.get('interactive') self.interactive = options.get('interactive')
self.show_traceback = options.get('traceback') self.show_traceback = options.get('traceback')
self.load_initial_data = options.get('load_initial_data') self.load_initial_data = options.get('load_initial_data')
self.test_database = options.get('test_database', False)
self.style = color_style() self.style = color_style()
@ -144,14 +145,14 @@ class Command(NoArgsCommand):
# Create the model's database table, if it doesn't already exist. # Create the model's database table, if it doesn't already exist.
if self.verbosity >= 3: if self.verbosity >= 3:
self.stdout.write(" Processing %s.%s model\n" % (app_name, model._meta.object_name)) self.stdout.write(" Processing %s.%s model\n" % (app_name, model._meta.object_name))
sql, references = connection.creation.sql_create_model(model, self.style, seen_models) sql, references = connection.creation.sql_create_model(model, no_style(), seen_models)
seen_models.add(model) seen_models.add(model)
created_models.add(model) created_models.add(model)
for refto, refs in references.items(): for refto, refs in references.items():
pending_references.setdefault(refto, []).extend(refs) pending_references.setdefault(refto, []).extend(refs)
if refto in seen_models: 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(refto, no_style(), pending_references))
sql.extend(connection.creation.sql_for_pending_references(model, self.style, pending_references)) sql.extend(connection.creation.sql_for_pending_references(model, no_style(), pending_references))
if self.verbosity >= 1 and sql: if self.verbosity >= 1 and sql:
self.stdout.write(" Creating table %s\n" % model._meta.db_table) self.stdout.write(" Creating table %s\n" % model._meta.db_table)
for statement in sql: for statement in sql:
@ -172,7 +173,7 @@ class Command(NoArgsCommand):
for app_name, model_list in manifest.items(): for app_name, model_list in manifest.items():
for model in model_list: for model in model_list:
if model in created_models: if model in created_models:
custom_sql = custom_sql_for_model(model, self.style, connection) custom_sql = custom_sql_for_model(model, no_style(), connection)
if custom_sql: if custom_sql:
if self.verbosity >= 2: if self.verbosity >= 2:
self.stdout.write(" Installing custom SQL for %s.%s model\n" % (app_name, model._meta.object_name)) self.stdout.write(" Installing custom SQL for %s.%s model\n" % (app_name, model._meta.object_name))
@ -194,7 +195,7 @@ class Command(NoArgsCommand):
for app_name, model_list in manifest.items(): for app_name, model_list in manifest.items():
for model in model_list: for model in model_list:
if model in created_models: if model in created_models:
index_sql = connection.creation.sql_indexes_for_model(model, self.style) index_sql = connection.creation.sql_indexes_for_model(model, no_style())
if index_sql: if index_sql:
if self.verbosity >= 2: if self.verbosity >= 2:
self.stdout.write(" Installing index for %s.%s model\n" % (app_name, model._meta.object_name)) self.stdout.write(" Installing index for %s.%s model\n" % (app_name, model._meta.object_name))

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@ -1,6 +1,8 @@
import re import re
from django.utils.six.moves import input
from django.db.migrations import operations from django.db.migrations import operations
from django.db.migrations.migration import Migration from django.db.migrations.migration import Migration
from django.db.models.loading import cache
class MigrationAutodetector(object): class MigrationAutodetector(object):
@ -16,9 +18,10 @@ class MigrationAutodetector(object):
if it wishes, with the caveat that it may not always be possible. if it wishes, with the caveat that it may not always be possible.
""" """
def __init__(self, from_state, to_state): def __init__(self, from_state, to_state, questioner=None):
self.from_state = from_state self.from_state = from_state
self.to_state = to_state self.to_state = to_state
self.questioner = questioner or MigrationQuestioner()
def changes(self): def changes(self):
""" """
@ -54,7 +57,7 @@ class MigrationAutodetector(object):
model_state.name, model_state.name,
) )
) )
# Alright, now sort out and return the migrations # Alright, now add internal dependencies
for app_label, migrations in self.migrations.items(): for app_label, migrations in self.migrations.items():
for m1, m2 in zip(migrations, migrations[1:]): for m1, m2 in zip(migrations, migrations[1:]):
m2.dependencies.append((app_label, m1.name)) m2.dependencies.append((app_label, m1.name))
@ -68,6 +71,77 @@ class MigrationAutodetector(object):
migrations.append(instance) migrations.append(instance)
migrations[-1].operations.append(operation) migrations[-1].operations.append(operation)
def arrange_for_graph(self, changes, graph):
"""
Takes in a result from changes() and a MigrationGraph,
and fixes the names and dependencies of the changes so they
extend the graph from the leaf nodes for each app.
"""
leaves = graph.leaf_nodes()
name_map = {}
for app_label, migrations in list(changes.items()):
if not migrations:
continue
# Find the app label's current leaf node
app_leaf = None
for leaf in leaves:
if leaf[0] == app_label:
app_leaf = leaf
break
# Do they want an initial migration for this app?
if app_leaf is None and not self.questioner.ask_initial(app_label):
# They don't.
for migration in migrations:
name_map[(app_label, migration.name)] = (app_label, "__first__")
del changes[app_label]
# Work out the next number in the sequence
if app_leaf is None:
next_number = 1
else:
next_number = (self.parse_number(app_leaf[1]) or 0) + 1
# Name each migration
for i, migration in enumerate(migrations):
if i == 0 and app_leaf:
migration.dependencies.append(app_leaf)
if i == 0 and not app_leaf:
new_name = "0001_initial"
else:
new_name = "%04i_%s" % (next_number, self.suggest_name(migration.operations))
name_map[(app_label, migration.name)] = (app_label, new_name)
migration.name = new_name
# Now fix dependencies
for app_label, migrations in changes.items():
for migration in migrations:
migration.dependencies = [name_map.get(d, d) for d in migration.dependencies]
return changes
def trim_to_apps(self, changes, app_labels):
"""
Takes changes from arrange_for_graph and set of app labels and
returns a modified set of changes which trims out as many migrations
that are not in app_labels as possible.
Note that some other migrations may still be present, as they may be
required dependencies.
"""
# Gather other app dependencies in a first pass
app_dependencies = {}
for app_label, migrations in changes.items():
for migration in migrations:
for dep_app_label, name in migration.dependencies:
app_dependencies.setdefault(app_label, set()).add(dep_app_label)
required_apps = set(app_labels)
# Keep resolving till there's no change
old_required_apps = None
while old_required_apps != required_apps:
old_required_apps = set(required_apps)
for app_label in list(required_apps):
required_apps.update(app_dependencies.get(app_label, set()))
# Remove all migrations that aren't needed
for app_label in list(changes.keys()):
if app_label not in required_apps:
del changes[app_label]
return changes
@classmethod @classmethod
def suggest_name(cls, ops): def suggest_name(cls, ops):
""" """
@ -94,41 +168,40 @@ class MigrationAutodetector(object):
return int(name.split("_")[0]) return int(name.split("_")[0])
return None return None
@classmethod
def arrange_for_graph(cls, changes, graph): class MigrationQuestioner(object):
""" """
Takes in a result from changes() and a MigrationGraph, Gives the autodetector responses to questions it might have.
and fixes the names and dependencies of the changes so they This base class has a built-in noninteractive mode, but the
extend the graph from the leaf nodes for each app. interactive subclass is what the command-line arguments will use.
""" """
leaves = graph.leaf_nodes()
name_map = {} def __init__(self, defaults=None):
for app_label, migrations in changes.items(): self.defaults = defaults or {}
if not migrations:
continue def ask_initial(self, app_label):
# Find the app label's current leaf node "Should we create an initial migration for the app?"
app_leaf = None return self.defaults.get("ask_initial", False)
for leaf in leaves:
if leaf[0] == app_label:
app_leaf = leaf class InteractiveMigrationQuestioner(MigrationQuestioner):
break
# Work out the next number in the sequence def __init__(self, specified_apps=set()):
if app_leaf is None: self.specified_apps = specified_apps
next_number = 1
else: def _boolean_input(self, question):
next_number = (cls.parse_number(app_leaf[1]) or 0) + 1 result = input("%s " % question)
# Name each migration while len(result) < 1 or result[0].lower() not in "yn":
for i, migration in enumerate(migrations): result = input("Please answer yes or no: ")
if i == 0 and app_leaf: return result[0].lower() == "y"
migration.dependencies.append(app_leaf)
if i == 0 and not app_leaf: def ask_initial(self, app_label):
new_name = "0001_initial" # Don't ask for django.contrib apps
else: app = cache.get_app(app_label)
new_name = "%04i_%s" % (next_number, cls.suggest_name(migration.operations)) if app.__name__.startswith("django.contrib"):
name_map[(app_label, migration.name)] = (app_label, new_name) return False
migration.name = new_name # If it was specified on the command line, definitely true
# Now fix dependencies if app_label in self.specified_apps:
for app_label, migrations in changes.items(): return True
for migration in migrations: # Now ask
migration.dependencies = [name_map.get(d, d) for d in migration.dependencies] return self._boolean_input("Do you want to enable migrations for app '%s'?" % app_label)
return changes

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@ -49,7 +49,7 @@ class MigrationGraph(object):
a database. a database.
""" """
if node not in self.nodes: if node not in self.nodes:
raise ValueError("Node %r not a valid node" % node) raise ValueError("Node %r not a valid node" % (node, ))
return self.dfs(node, lambda x: self.dependencies.get(x, set())) return self.dfs(node, lambda x: self.dependencies.get(x, set()))
def backwards_plan(self, node): def backwards_plan(self, node):
@ -60,7 +60,7 @@ class MigrationGraph(object):
a database. a database.
""" """
if node not in self.nodes: if node not in self.nodes:
raise ValueError("Node %r not a valid node" % node) raise ValueError("Node %r not a valid node" % (node, ))
return self.dfs(node, lambda x: self.dependents.get(x, set())) return self.dfs(node, lambda x: self.dependents.get(x, set()))
def root_nodes(self): def root_nodes(self):
@ -120,11 +120,16 @@ class MigrationGraph(object):
def __str__(self): def __str__(self):
return "Graph: %s nodes, %s edges" % (len(self.nodes), sum(len(x) for x in self.dependencies.values())) return "Graph: %s nodes, %s edges" % (len(self.nodes), sum(len(x) for x in self.dependencies.values()))
def project_state(self, nodes, at_end=True): def project_state(self, nodes=None, at_end=True):
""" """
Given a migration node or nodes, returns a complete ProjectState for it. Given a migration node or nodes, returns a complete ProjectState for it.
If at_end is False, returns the state before the migration has run. If at_end is False, returns the state before the migration has run.
If nodes is not provided, returns the overall most current project state.
""" """
if nodes is None:
nodes = list(self.leaf_nodes())
if len(nodes) == 0:
return ProjectState()
if not isinstance(nodes[0], tuple): if not isinstance(nodes[0], tuple):
nodes = [nodes] nodes = [nodes]
plan = [] plan = []

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@ -60,3 +60,10 @@ class MigrationRecorder(object):
""" """
self.ensure_schema() self.ensure_schema()
self.Migration.objects.filter(app=app, name=name).delete() self.Migration.objects.filter(app=app, name=name).delete()
@classmethod
def flush(cls):
"""
Deletes all migration records. Useful if you're testing migrations.
"""
cls.Migration.objects.all().delete()

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@ -1,12 +1,12 @@
# encoding: utf8 # encoding: utf8
from django.test import TransactionTestCase from django.test import TestCase
from django.db.migrations.autodetector import MigrationAutodetector from django.db.migrations.autodetector import MigrationAutodetector, MigrationQuestioner
from django.db.migrations.state import ProjectState, ModelState from django.db.migrations.state import ProjectState, ModelState
from django.db.migrations.graph import MigrationGraph from django.db.migrations.graph import MigrationGraph
from django.db import models from django.db import models
class AutodetectorTests(TransactionTestCase): class AutodetectorTests(TestCase):
""" """
Tests the migration autodetector. Tests the migration autodetector.
""" """
@ -14,6 +14,7 @@ class AutodetectorTests(TransactionTestCase):
author_empty = ModelState("testapp", "Author", [("id", models.AutoField(primary_key=True))]) author_empty = ModelState("testapp", "Author", [("id", models.AutoField(primary_key=True))])
other_pony = ModelState("otherapp", "Pony", [("id", models.AutoField(primary_key=True))]) other_pony = ModelState("otherapp", "Pony", [("id", models.AutoField(primary_key=True))])
other_stable = ModelState("otherapp", "Stable", [("id", models.AutoField(primary_key=True))]) other_stable = ModelState("otherapp", "Stable", [("id", models.AutoField(primary_key=True))])
third_thing = ModelState("thirdapp", "Thing", [("id", models.AutoField(primary_key=True))])
def make_project_state(self, model_states): def make_project_state(self, model_states):
"Shortcut to make ProjectStates from lists of predefined models" "Shortcut to make ProjectStates from lists of predefined models"
@ -44,6 +45,23 @@ class AutodetectorTests(TransactionTestCase):
self.assertEqual(changes["otherapp"][0].name, "0002_pony_stable") self.assertEqual(changes["otherapp"][0].name, "0002_pony_stable")
self.assertEqual(changes["otherapp"][0].dependencies, [("otherapp", "0001_initial")]) self.assertEqual(changes["otherapp"][0].dependencies, [("otherapp", "0001_initial")])
def test_trim_apps(self):
"Tests that trim does not remove dependencies but does remove unwanted apps"
# Use project state to make a new migration change set
before = self.make_project_state([])
after = self.make_project_state([self.author_empty, self.other_pony, self.other_stable, self.third_thing])
autodetector = MigrationAutodetector(before, after, MigrationQuestioner({"ask_initial": True}))
changes = autodetector.changes()
# Run through arrange_for_graph
graph = MigrationGraph()
changes = autodetector.arrange_for_graph(changes, graph)
changes["testapp"][0].dependencies.append(("otherapp", "0001_initial"))
changes = autodetector.trim_to_apps(changes, set(["testapp"]))
# Make sure there's the right set of migrations
self.assertEqual(changes["testapp"][0].name, "0001_initial")
self.assertEqual(changes["otherapp"][0].name, "0001_initial")
self.assertNotIn("thirdapp", changes)
def test_new_model(self): def test_new_model(self):
"Tests autodetection of new models" "Tests autodetection of new models"
# Make state # Make state

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@ -18,6 +18,8 @@ class SchemaTests(TransactionTestCase):
as the code it is testing. as the code it is testing.
""" """
available_apps = []
models = [Author, AuthorWithM2M, Book, BookWithSlug, BookWithM2M, Tag, TagUniqueRename, UniqueTest] models = [Author, AuthorWithM2M, Book, BookWithSlug, BookWithM2M, Tag, TagUniqueRename, UniqueTest]
no_table_strings = ["no such table", "unknown table", "does not exist"] no_table_strings = ["no such table", "unknown table", "does not exist"]