94 lines
3.5 KiB
Python
94 lines
3.5 KiB
Python
"""
|
|
Firebird database specific implementations of changeset classes.
|
|
"""
|
|
from sqlalchemy.databases import firebird as sa_base
|
|
from sqlalchemy.schema import PrimaryKeyConstraint
|
|
from migrate import exceptions
|
|
from migrate.changeset import ansisql
|
|
|
|
|
|
FBSchemaGenerator = sa_base.FBDDLCompiler
|
|
|
|
class FBColumnGenerator(FBSchemaGenerator, ansisql.ANSIColumnGenerator):
|
|
"""Firebird column generator implementation."""
|
|
|
|
|
|
class FBColumnDropper(ansisql.ANSIColumnDropper):
|
|
"""Firebird column dropper implementation."""
|
|
|
|
def visit_column(self, column):
|
|
"""Firebird supports 'DROP col' instead of 'DROP COLUMN col' syntax
|
|
|
|
Drop primary key and unique constraints if dropped column is referencing it."""
|
|
if column.primary_key:
|
|
if column.table.primary_key.columns.contains_column(column):
|
|
column.table.primary_key.drop()
|
|
# TODO: recreate primary key if it references more than this column
|
|
|
|
for index in column.table.indexes:
|
|
# "column in index.columns" causes problems as all
|
|
# column objects compare equal and return a SQL expression
|
|
if column.name in [col.name for col in index.columns]:
|
|
index.drop()
|
|
# TODO: recreate index if it references more than this column
|
|
|
|
for cons in column.table.constraints:
|
|
if isinstance(cons,PrimaryKeyConstraint):
|
|
# will be deleted only when the column its on
|
|
# is deleted!
|
|
continue
|
|
|
|
should_drop = column.name in cons.columns
|
|
if should_drop:
|
|
self.start_alter_table(column)
|
|
self.append("DROP CONSTRAINT ")
|
|
self.append(self.preparer.format_constraint(cons))
|
|
self.execute()
|
|
# TODO: recreate unique constraint if it refenrences more than this column
|
|
|
|
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)
|
|
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
|