2009-07-13 18:45:52 +02:00

66 lines
2.2 KiB
Python

"""
Firebird database specific implementations of changeset classes.
"""
from migrate.changeset import ansisql, exceptions, SQLA_06
from sqlalchemy.databases import firebird as sa_base
if SQLA_06:
FBSchemaGenerator = sa_base.FBDDLCompiler
else:
FBSchemaGenerator = sa_base.FBSchemaGenerator
class FBColumnGenerator(FBSchemaGenerator, ansisql.ANSIColumnGenerator):
"""Firebird column generator implementation."""
class FBColumnDropper(ansisql.ANSIColumnDropper):
"""Firebird column dropper implementation."""
def visit_column(self, column):
table = self.start_alter_table(column)
self.append('DROP %s' % self.preparer.format_column(column))
self.execute()
class FBSchemaChanger(ansisql.ANSISchemaChanger):
"""Firebird schema changer implementation."""
def visit_table(self, table):
"""Rename table not supported"""
raise exceptions.NotSupportedError(
"Firebird does not support renaming tables.")
def _visit_column_name(self, table, column, delta):
self.start_alter_table(table)
col_name = self.preparer.quote(delta.current_name, table.quote)
new_name = self.preparer.format_column(delta.result_column)
self.append('ALTER COLUMN %s TO %s' % (col_name, new_name))
def _visit_column_nullable(self, table, column, delta):
"""Changing NULL is not supported"""
# TODO: http://www.firebirdfaq.org/faq103/
raise exceptions.NotSupportedError(
"Firebird does not support altering NULL bevahior.")
class FBConstraintGenerator(ansisql.ANSIConstraintGenerator):
"""Firebird constraint generator implementation."""
class FBConstraintDropper(ansisql.ANSIConstraintDropper):
"""Firebird constaint dropper implementation."""
def cascade_constraint(self, constraint):
"""Cascading constraints is not supported"""
raise exceptions.NotSupportedError(
"Firebird does not support cascading constraints")
class FBDialect(ansisql.ANSIDialect):
columngenerator = FBColumnGenerator
columndropper = FBColumnDropper
schemachanger = FBSchemaChanger
constraintgenerator = FBConstraintGenerator
constraintdropper = FBConstraintDropper