|
|
"""
|
|
|
Schema differencing support.
|
|
|
"""
|
|
|
|
|
|
import logging
|
|
|
import sqlalchemy
|
|
|
|
|
|
from sqlalchemy.types import Float
|
|
|
|
|
|
log = logging.getLogger(__name__)
|
|
|
|
|
|
|
|
|
def getDiffOfModelAgainstDatabase(metadata, engine, excludeTables=None):
|
|
|
"""
|
|
|
Return differences of model against database.
|
|
|
|
|
|
:return: object which will evaluate to :keyword:`True` if there \
|
|
|
are differences else :keyword:`False`.
|
|
|
"""
|
|
|
db_metadata = sqlalchemy.MetaData(engine)
|
|
|
db_metadata.reflect()
|
|
|
|
|
|
# sqlite will include a dynamically generated 'sqlite_sequence' table if
|
|
|
# there are autoincrement sequences in the database; this should not be
|
|
|
# compared.
|
|
|
if engine.dialect.name == 'sqlite':
|
|
|
if 'sqlite_sequence' in db_metadata.tables:
|
|
|
db_metadata.remove(db_metadata.tables['sqlite_sequence'])
|
|
|
|
|
|
return SchemaDiff(metadata, db_metadata,
|
|
|
labelA='model',
|
|
|
labelB='database',
|
|
|
excludeTables=excludeTables)
|
|
|
|
|
|
|
|
|
def getDiffOfModelAgainstModel(metadataA, metadataB, excludeTables=None):
|
|
|
"""
|
|
|
Return differences of model against another model.
|
|
|
|
|
|
:return: object which will evaluate to :keyword:`True` if there \
|
|
|
are differences else :keyword:`False`.
|
|
|
"""
|
|
|
return SchemaDiff(metadataA, metadataB, excludeTables=excludeTables)
|
|
|
|
|
|
|
|
|
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.
|
|
|
|
|
|
.. attribute:: type_A
|
|
|
|
|
|
The most generic type of the :class:`~sqlalchemy.schema.Column`
|
|
|
object in A.
|
|
|
|
|
|
.. attribute:: type_B
|
|
|
|
|
|
The most generic type of the :class:`~sqlalchemy.schema.Column`
|
|
|
object in A.
|
|
|
|
|
|
"""
|
|
|
|
|
|
diff = False
|
|
|
|
|
|
def __init__(self,col_A,col_B):
|
|
|
self.col_A = col_A
|
|
|
self.col_B = col_B
|
|
|
|
|
|
self.type_A = col_A.type
|
|
|
self.type_B = col_B.type
|
|
|
|
|
|
self.affinity_A = self.type_A._type_affinity
|
|
|
self.affinity_B = self.type_B._type_affinity
|
|
|
|
|
|
if self.affinity_A is not self.affinity_B:
|
|
|
self.diff = True
|
|
|
return
|
|
|
|
|
|
if isinstance(self.type_A,Float) or isinstance(self.type_B,Float):
|
|
|
if not (isinstance(self.type_A,Float) and isinstance(self.type_B,Float)):
|
|
|
self.diff=True
|
|
|
return
|
|
|
|
|
|
for attr in ('precision','scale','length'):
|
|
|
A = getattr(self.type_A,attr,None)
|
|
|
B = getattr(self.type_B,attr,None)
|
|
|
if not (A is None or B is None) and A!=B:
|
|
|
self.diff=True
|
|
|
return
|
|
|
|
|
|
def __nonzero__(self):
|
|
|
return self.diff
|
|
|
|
|
|
__bool__ = __nonzero__
|
|
|
|
|
|
|
|
|
class TableDiff(object):
|
|
|
"""
|
|
|
Container for differences in one :class:`~sqlalchemy.schema.Table`
|
|
|
between two :class:`~sqlalchemy.schema.MetaData` instances, ``A``
|
|
|
and ``B``.
|
|
|
|
|
|
.. attribute:: columns_missing_from_A
|
|
|
|
|
|
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
|
|
|
found to be different.
|
|
|
It maps column names to a :class:`ColDiff` objects describing the
|
|
|
differences found.
|
|
|
"""
|
|
|
__slots__ = (
|
|
|
'columns_missing_from_A',
|
|
|
'columns_missing_from_B',
|
|
|
'columns_different',
|
|
|
)
|
|
|
|
|
|
def __nonzero__(self):
|
|
|
return bool(
|
|
|
self.columns_missing_from_A or
|
|
|
self.columns_missing_from_B or
|
|
|
self.columns_different
|
|
|
)
|
|
|
|
|
|
__bool__ = __nonzero__
|
|
|
|
|
|
class SchemaDiff(object):
|
|
|
"""
|
|
|
Compute the difference between two :class:`~sqlalchemy.schema.MetaData`
|
|
|
objects.
|
|
|
|
|
|
The string representation of a :class:`SchemaDiff` will summarise
|
|
|
the changes found between the two
|
|
|
:class:`~sqlalchemy.schema.MetaData` objects.
|
|
|
|
|
|
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:
|
|
|
The label to use in messages about the second
|
|
|
: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
|
|
|
to be different.
|
|
|
It maps table names to a :class:`TableDiff` objects describing the
|
|
|
differences found.
|
|
|
"""
|
|
|
|
|
|
def __init__(self,
|
|
|
metadataA, metadataB,
|
|
|
labelA='metadataA',
|
|
|
labelB='metadataB',
|
|
|
excludeTables=None):
|
|
|
|
|
|
self.metadataA, self.metadataB = metadataA, metadataB
|
|
|
self.labelA, self.labelB = labelA, labelB
|
|
|
self.label_width = max(len(labelA),len(labelB))
|
|
|
excludeTables = set(excludeTables or [])
|
|
|
|
|
|
A_table_names = set(metadataA.tables.keys())
|
|
|
B_table_names = set(metadataB.tables.keys())
|
|
|
|
|
|
self.tables_missing_from_A = sorted(
|
|
|
B_table_names - A_table_names - excludeTables
|
|
|
)
|
|
|
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):
|
|
|
|
|
|
cd = ColDiff(
|
|
|
A_table.columns.get(col_name),
|
|
|
B_table.columns.get(col_name)
|
|
|
)
|
|
|
|
|
|
if cd:
|
|
|
td.columns_different[col_name]=cd
|
|
|
|
|
|
# XXX - index and constraint differences should
|
|
|
# be checked for here
|
|
|
|
|
|
if td:
|
|
|
self.tables_different[table_name]=td
|
|
|
|
|
|
def __str__(self):
|
|
|
""" 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),
|
|
|
):
|
|
|
if names:
|
|
|
out.append(
|
|
|
' tables missing from %s: %s' % (
|
|
|
label,', '.join(sorted(names))
|
|
|
)
|
|
|
)
|
|
|
|
|
|
for name,td in sorted(self.tables_different.items()):
|
|
|
out.append(
|
|
|
' table with differences: %s' % name
|
|
|
)
|
|
|
for names,label in (
|
|
|
(td.columns_missing_from_A,self.labelA),
|
|
|
(td.columns_missing_from_B,self.labelB),
|
|
|
):
|
|
|
if names:
|
|
|
out.append(
|
|
|
' %s missing these columns: %s' % (
|
|
|
label,', '.join(sorted(names))
|
|
|
)
|
|
|
)
|
|
|
for name,cd in list(td.columns_different.items()):
|
|
|
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)
|
|
|
else:
|
|
|
return 'No schema diffs'
|
|
|
|
|
|
def __len__(self):
|
|
|
"""
|
|
|
Used in bool evaluation, return of 0 means no diffs.
|
|
|
"""
|
|
|
return (
|
|
|
len(self.tables_missing_from_A) +
|
|
|
len(self.tables_missing_from_B) +
|
|
|
len(self.tables_different)
|
|
|
)
|
|
|
|
