x/sqlalchemy-migrate
Code Issues Proposed changes

Fix and test issue 118. Clarify genmodel transformations.

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This commit is contained in:
Gabriel 2011-07-05 00:44:57 +02:00
parent 5cfc74959f
commit 3fe1b4a3be
6 changed files with 159 additions and 99 deletions
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64
migrate/tests/versioning/test_genmodel.py
View File

@ -35,7 +35,7 @@ class TestSchemaDiff(fixture.DB):
def _applyLatestModel(self):
diff = schemadiff.getDiffOfModelAgainstDatabase(self.meta, self.engine, excludeTables=['migrate_version'])
genmodel.ModelGenerator(diff,self.engine).applyModel()
genmodel.ModelGenerator(diff,self.engine).runB2A()
@fixture.usedb()
def test_functional(self):
@ -57,30 +57,44 @@ class TestSchemaDiff(fixture.DB):
# Check Python upgrade and downgrade of database from updated model.
diff = schemadiff.getDiffOfModelAgainstDatabase(self.meta, self.engine, excludeTables=['migrate_version'])
decls, upgradeCommands, downgradeCommands = genmodel.ModelGenerator(diff,self.engine).toUpgradeDowngradePython()
self.assertEqualsIgnoreWhitespace(decls, '''
from migrate.changeset import schema
meta = MetaData()
tmp_schemadiff = Table('tmp_schemadiff', meta,
Column('id', Integer(), primary_key=True, nullable=False),
Column('name', UnicodeText(length=None)),
Column('data', UnicodeText(length=None)),
)
''')
decls, upgradeCommands, downgradeCommands = genmodel.ModelGenerator(diff,self.engine).genB2AMigration()
# Feature test for a recent SQLa feature;
# expect different output in that case.
if repr(String()) == 'String()':
self.assertEqualsIgnoreWhitespace(decls, '''
from migrate.changeset import schema
meta = MetaData()
tmp_schemadiff = Table('tmp_schemadiff', meta,
Column('id', Integer, primary_key=True, nullable=False),
Column('name', UnicodeText),
Column('data', UnicodeText),
)
''')
else:
self.assertEqualsIgnoreWhitespace(decls, '''
from migrate.changeset import schema
meta = MetaData()
tmp_schemadiff = Table('tmp_schemadiff', meta,
Column('id', Integer(), primary_key=True, nullable=False),
Column('name', UnicodeText(length=None)),
Column('data', UnicodeText(length=None)),
)
''')
self.assertEqualsIgnoreWhitespace(upgradeCommands,
'''meta.bind = migrate_engine
tmp_schemadiff.create()''')
self.assertEqualsIgnoreWhitespace(downgradeCommands,
'''meta.bind = migrate_engine
tmp_schemadiff.drop()''')
# Create table in database, now model should match database.
self._applyLatestModel()
assertDiff(False, [], [], [])
# Check Python code gen from database.
diff = schemadiff.getDiffOfModelAgainstDatabase(MetaData(), self.engine, excludeTables=['migrate_version'])
src = genmodel.ModelGenerator(diff,self.engine).toPython()
src = genmodel.ModelGenerator(diff,self.engine).genBDefinition()
exec src in locals()
@ -105,25 +119,25 @@ class TestSchemaDiff(fixture.DB):
Column('data2',Integer(),nullable=True),
)
assertDiff(True, [], [], [self.table_name])
# Apply latest model changes and find no more diffs.
self._applyLatestModel()
assertDiff(False, [], [], [])
if not self.engine.name == 'oracle':
# Make sure data is still present.
result = self.engine.execute(self.table.select(self.table.c.id==dataId))
rows = result.fetchall()
eq_(len(rows), 1)
eq_(rows[0].name, 'mydata')
# Add data, later we'll make sure it's still present.
result = self.engine.execute(self.table.insert(), id=2, name=u'mydata2', data2=123)
if SQLA_06:
dataId2 = result.inserted_primary_key[0]
else:
dataId2 = result.last_inserted_ids()[0]
# Change column type in model.
self.meta.remove(self.table)
self.table = Table(self.table_name,self.meta,
@ -134,13 +148,13 @@ class TestSchemaDiff(fixture.DB):
# XXX test type diff
return
assertDiff(True, [], [], [self.table_name])
# Apply latest model changes and find no more diffs.
self._applyLatestModel()
assertDiff(False, [], [], [])
if not self.engine.name == 'oracle':
# Make sure data is still present.
result = self.engine.execute(self.table.select(self.table.c.id==dataId2))
@ -148,11 +162,11 @@ class TestSchemaDiff(fixture.DB):
self.assertEquals(len(rows), 1)
self.assertEquals(rows[0].name, 'mydata2')
self.assertEquals(rows[0].data2, '123')
# Delete data, since we're about to make a required column.
# Not even using sqlalchemy.PassiveDefault helps because we're doing explicit column select.
self.engine.execute(self.table.delete(), id=dataId)
if not self.engine.name == 'firebird':
# Change column nullable in model.
self.meta.remove(self.table)
@ -162,11 +176,11 @@ class TestSchemaDiff(fixture.DB):
Column('data2',String(255),nullable=False),
)
assertDiff(True, [], [], [self.table_name]) # TODO test nullable diff
# Apply latest model changes and find no more diffs.
self._applyLatestModel()
assertDiff(False, [], [], [])
# Remove table from model.
self.meta.remove(self.table)
assertDiff(True, [], [self.table_name], [])

51
migrate/tests/versioning/test_script.py
View File

@ -161,23 +161,44 @@ def upgrade(migrate_engine):
self.assertTrue('User.create()' in source_script)
self.assertTrue('User.drop()' in source_script)
#@fixture.usedb()
#def test_make_update_script_for_model_equals(self):
# """Try to make update script from two identical models"""
@fixture.usedb()
def test_make_update_script_for_equal_models(self):
"""Try to make update script from two identical models"""
# self.setup_model_params()
# self.write_file(self.first_model_path, self.base_source + self.model_source)
# self.write_file(self.second_model_path, self.base_source + self.model_source)
self.setup_model_params()
self.write_file(self.first_model_path, self.base_source + self.model_source)
self.write_file(self.second_model_path, self.base_source + self.model_source)
# source_script = self.pyscript.make_update_script_for_model(
# engine=self.engine,
# oldmodel=load_model('testmodel_first:meta'),
# model=load_model('testmodel_second:meta'),
# repository=self.repo_path,
# )
source_script = self.pyscript.make_update_script_for_model(
engine=self.engine,
oldmodel=load_model('testmodel_first:meta'),
model=load_model('testmodel_second:meta'),
repository=self.repo_path,
)
# self.assertFalse('User.create()' in source_script)
# self.assertFalse('User.drop()' in source_script)
self.assertFalse('User.create()' in source_script)
self.assertFalse('User.drop()' in source_script)
@fixture.usedb()
def test_make_update_script_direction(self):
"""Check update scripts go in the right direction"""
self.setup_model_params()
self.write_file(self.first_model_path, self.base_source)
self.write_file(self.second_model_path, self.base_source + self.model_source)
source_script = self.pyscript.make_update_script_for_model(
engine=self.engine,
oldmodel=load_model('testmodel_first:meta'),
model=load_model('testmodel_second:meta'),
repository=self.repo_path,
)
self.assertTrue(0
< source_script.find('upgrade')
< source_script.find('User.create()')
< source_script.find('downgrade')
< source_script.find('User.drop()'))
def setup_model_params(self):
self.script_path = self.tmp_py()
@ -195,6 +216,8 @@ User = Table('User', meta,
self.repo = repository.Repository.create(self.repo_path, 'repo')
self.pyscript = PythonScript.create(self.script_path)
sys.modules.pop('testmodel_first', None)
sys.modules.pop('testmodel_second', None)
def write_file(self, path, contents):
f = open(path, 'w')

57
migrate/versioning/genmodel.py
View File

@ -1,9 +1,9 @@
"""
Code to generate a Python model from a database or differences
between a model and database.
Code to generate a Python model from a database or differences
between a model and database.
Some of this is borrowed heavily from the AutoCode project at:
http://code.google.com/p/sqlautocode/
Some of this is borrowed heavily from the AutoCode project at:
http://code.google.com/p/sqlautocode/
"""
import sys
@ -34,6 +34,13 @@ Base = declarative.declarative_base()
class ModelGenerator(object):
"""Various transformations from an A, B diff.
In the implementation, A tends to be called the model and B
the database (although this is not true of all diffs).
The diff is directionless, but transformations apply the diff
in a particular direction, described in the method name.
"""
def __init__(self, diff, engine, declarative=False):
self.diff = diff
@ -89,7 +96,7 @@ class ModelGenerator(object):
else:
return """Column(%(name)r, %(commonStuff)s)""" % data
def getTableDefn(self, table):
def _getTableDefn(self, table):
out = []
tableName = table.name
if self.declarative:
@ -117,9 +124,15 @@ class ModelGenerator(object):
if bool_:
for name in names:
yield metadata.tables.get(name)
def toPython(self):
"""Assume database is current and model is empty."""
def genBDefinition(self):
"""Generates the source code for a definition of B.
Assumes a diff where A is empty.
Was: toPython. Assume database (B) is current and model (A) is empty.
"""
out = []
if self.declarative:
out.append(DECLARATIVE_HEADER)
@ -127,17 +140,22 @@ class ModelGenerator(object):
out.append(HEADER)
out.append("")
for table in self._get_tables(missingA=True):
out.extend(self.getTableDefn(table))
out.extend(self._getTableDefn(table))
return '\n'.join(out)
def toUpgradeDowngradePython(self, indent=' '):
''' Assume model is most current and database is out-of-date. '''
def genB2AMigration(self, indent=' '):
'''Generate a migration from B to A.
Was: toUpgradeDowngradePython
Assume model (A) is most current and database (B) is out-of-date.
'''
decls = ['from migrate.changeset import schema',
'meta = MetaData()']
for table in self._get_tables(
missingA=True,missingB=True,modified=True
):
decls.extend(self.getTableDefn(table))
decls.extend(self._getTableDefn(table))
upgradeCommands, downgradeCommands = [], []
for tableName in self.diff.tables_missing_from_A:
@ -175,16 +193,21 @@ class ModelGenerator(object):
'\n'.join([pre_command] + ['%s%s' % (indent, line) for line in downgradeCommands]))
def _db_can_handle_this_change(self,td):
"""Check if the database can handle going from B to A."""
if (td.columns_missing_from_B
and not td.columns_missing_from_A
and not td.columns_different):
# Even sqlite can handle this.
# Even sqlite can handle column additions.
return True
else:
return not self.engine.url.drivername.startswith('sqlite')
def applyModel(self):
"""Apply model to current database."""
def runB2A(self):
"""Goes from B to A.
Was: applyModel. Apply model (A) to current database (B).
"""
meta = sqlalchemy.MetaData(self.engine)
@ -200,9 +223,9 @@ class ModelGenerator(object):
dbTable = self.diff.metadataB.tables[tableName]
td = self.diff.tables_different[tableName]
if self._db_can_handle_this_change(td):
for col in td.columns_missing_from_B:
modelTable.columns[col].create()
for col in td.columns_missing_from_A:

6
migrate/versioning/schema.py
View File

@ -71,7 +71,7 @@ class ControlledSchema(object):
def changeset(self, version=None):
"""API to Changeset creation.
Uses self.version for start version and engine.name
to get database name.
"""
@ -117,7 +117,7 @@ class ControlledSchema(object):
diff = schemadiff.getDiffOfModelAgainstDatabase(
model, self.engine, excludeTables=[self.repository.version_table]
)
genmodel.ModelGenerator(diff,self.engine).applyModel()
genmodel.ModelGenerator(diff,self.engine).runB2A()
self.update_repository_table(self.version, int(self.repository.latest))
@ -217,4 +217,4 @@ class ControlledSchema(object):
diff = schemadiff.getDiffOfModelAgainstDatabase(
MetaData(), engine, excludeTables=[repository.version_table]
)
return genmodel.ModelGenerator(diff, engine, declarative).toPython()
return genmodel.ModelGenerator(diff, engine, declarative).genBDefinition()

64
migrate/versioning/schemadiff.py
View File

@ -39,11 +39,11 @@ class ColDiff(object):
Container for differences in one :class:`~sqlalchemy.schema.Column`
between two :class:`~sqlalchemy.schema.Table` instances, ``A``
and ``B``.
.. attribute:: col_A
The :class:`~sqlalchemy.schema.Column` object for A.
.. attribute:: col_B
The :class:`~sqlalchemy.schema.Column` object for B.
@ -51,15 +51,15 @@ class ColDiff(object):
.. attribute:: type_A
The most generic type of the :class:`~sqlalchemy.schema.Column`
object in A.
object in A.
.. attribute:: type_B
The most generic type of the :class:`~sqlalchemy.schema.Column`
object in A.
object in A.
"""
diff = False
def __init__(self,col_A,col_B):
@ -87,10 +87,10 @@ class ColDiff(object):
if not (A is None or B is None) and A!=B:
self.diff=True
return
def __nonzero__(self):
return self.diff
class TableDiff(object):
"""
Container for differences in one :class:`~sqlalchemy.schema.Table`
@ -101,12 +101,12 @@ class TableDiff(object):
A sequence of column names that were found in B but weren't in
A.
.. attribute:: columns_missing_from_B
A sequence of column names that were found in A but weren't in
B.
.. attribute:: columns_different
A dictionary containing information about columns that were
@ -126,7 +126,7 @@ class TableDiff(object):
self.columns_missing_from_B or
self.columns_different
)
class SchemaDiff(object):
"""
Compute the difference between two :class:`~sqlalchemy.schema.MetaData`
@ -139,34 +139,34 @@ class SchemaDiff(object):
The length of a :class:`SchemaDiff` will give the number of
changes found, enabling it to be used much like a boolean in
expressions.
:param metadataA:
First :class:`~sqlalchemy.schema.MetaData` to compare.
:param metadataB:
Second :class:`~sqlalchemy.schema.MetaData` to compare.
:param labelA:
The label to use in messages about the first
:class:`~sqlalchemy.schema.MetaData`.
:param labelB:
:class:`~sqlalchemy.schema.MetaData`.
:param labelB:
The label to use in messages about the second
:class:`~sqlalchemy.schema.MetaData`.
:class:`~sqlalchemy.schema.MetaData`.
:param excludeTables:
A sequence of table names to exclude.
.. attribute:: tables_missing_from_A
A sequence of table names that were found in B but weren't in
A.
.. attribute:: tables_missing_from_B
A sequence of table names that were found in A but weren't in
B.
.. attribute:: tables_different
A dictionary containing information about tables that were found
@ -195,26 +195,26 @@ class SchemaDiff(object):
self.tables_missing_from_B = sorted(
A_table_names - B_table_names - excludeTables
)
self.tables_different = {}
for table_name in A_table_names.intersection(B_table_names):
td = TableDiff()
A_table = metadataA.tables[table_name]
B_table = metadataB.tables[table_name]
A_column_names = set(A_table.columns.keys())
B_column_names = set(B_table.columns.keys())
td.columns_missing_from_A = sorted(
B_column_names - A_column_names
)
td.columns_missing_from_B = sorted(
A_column_names - B_column_names
)
td.columns_different = {}
for col_name in A_column_names.intersection(B_column_names):
@ -226,7 +226,7 @@ class SchemaDiff(object):
if cd:
td.columns_different[col_name]=cd
# XXX - index and constraint differences should
# be checked for here
@ -237,7 +237,7 @@ class SchemaDiff(object):
''' Summarize differences. '''
out = []
column_template =' %%%is: %%r' % self.label_width
for names,label in (
(self.tables_missing_from_A,self.labelA),
(self.tables_missing_from_B,self.labelB),
@ -248,7 +248,7 @@ class SchemaDiff(object):
label,', '.join(sorted(names))
)
)
for name,td in sorted(self.tables_different.items()):
out.append(
' table with differences: %s' % name
@ -267,7 +267,7 @@ class SchemaDiff(object):
out.append(' column with differences: %s' % name)
out.append(column_template % (self.labelA,cd.col_A))
out.append(column_template % (self.labelB,cd.col_B))
if out:
out.insert(0, 'Schema diffs:')
return '\n'.join(out)

16
migrate/versioning/script/py.py
View File

@ -25,7 +25,7 @@ class PythonScript(base.BaseScript):
@classmethod
def create(cls, path, **opts):
"""Create an empty migration script at specified path
:returns: :class:`PythonScript instance <migrate.versioning.script.py.PythonScript>`"""
cls.require_notfound(path)
@ -38,7 +38,7 @@ class PythonScript(base.BaseScript):
def make_update_script_for_model(cls, engine, oldmodel,
model, repository, **opts):
"""Create a migration script based on difference between two SA models.
:param repository: path to migrate repository
:param oldmodel: dotted.module.name:SAClass or SAClass object
:param model: dotted.module.name:SAClass or SAClass object
@ -50,7 +50,7 @@ class PythonScript(base.BaseScript):
:returns: Upgrade / Downgrade script
:rtype: string
"""
if isinstance(repository, basestring):
# oh dear, an import cycle!
from migrate.versioning.repository import Repository
@ -61,12 +61,12 @@ class PythonScript(base.BaseScript):
# Compute differences.
diff = schemadiff.getDiffOfModelAgainstModel(
oldmodel,
model,
oldmodel,
excludeTables=[repository.version_table])
# TODO: diff can be False (there is no difference?)
decls, upgradeCommands, downgradeCommands = \
genmodel.ModelGenerator(diff,engine).toUpgradeDowngradePython()
genmodel.ModelGenerator(diff,engine).genB2AMigration()
# Store differences into file.
src = Template(opts.pop('templates_path', None)).get_script(opts.pop('templates_theme', None))
@ -86,7 +86,7 @@ class PythonScript(base.BaseScript):
@classmethod
def verify_module(cls, path):
"""Ensure path is a valid script
:param path: Script location
:type path: string
:raises: :exc:`InvalidScriptError <migrate.exceptions.InvalidScriptError>`
@ -101,7 +101,7 @@ class PythonScript(base.BaseScript):
return module
def preview_sql(self, url, step, **args):
"""Mocks SQLAlchemy Engine to store all executed calls in a string
"""Mocks SQLAlchemy Engine to store all executed calls in a string
and runs :meth:`PythonScript.run <migrate.versioning.script.py.PythonScript.run>`
:returns: SQL file
@ -119,7 +119,7 @@ class PythonScript(base.BaseScript):
return go(url, step, **args)
def run(self, engine, step):
"""Core method of Script file.
"""Core method of Script file.
Exectues :func:`update` or :func:`downgrade` functions
:param engine: SQLAlchemy Engine