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oracle.py
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| text/x-python
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r1 | """ | |||
Oracle database specific implementations of changeset classes. | ||||
""" | ||||
import sqlalchemy as sa | ||||
from sqlalchemy.databases import oracle as sa_base | ||||
from rhodecode.lib.dbmigrate.migrate import exceptions | ||||
from rhodecode.lib.dbmigrate.migrate.changeset import ansisql | ||||
OracleSchemaGenerator = sa_base.OracleDDLCompiler | ||||
class OracleColumnGenerator(OracleSchemaGenerator, ansisql.ANSIColumnGenerator): | ||||
pass | ||||
class OracleColumnDropper(ansisql.ANSIColumnDropper): | ||||
pass | ||||
class OracleSchemaChanger(OracleSchemaGenerator, ansisql.ANSISchemaChanger): | ||||
def get_column_specification(self, column, **kwargs): | ||||
# Ignore the NOT NULL generated | ||||
override_nullable = kwargs.pop('override_nullable', None) | ||||
if override_nullable: | ||||
orig = column.nullable | ||||
column.nullable = True | ||||
ret = super(OracleSchemaChanger, self).get_column_specification( | ||||
column, **kwargs) | ||||
if override_nullable: | ||||
column.nullable = orig | ||||
return ret | ||||
def visit_column(self, delta): | ||||
keys = delta.keys() | ||||
if 'name' in keys: | ||||
self._run_subvisit(delta, | ||||
self._visit_column_name, | ||||
start_alter=False) | ||||
if len(set(('type', 'nullable', 'server_default')).intersection(keys)): | ||||
self._run_subvisit(delta, | ||||
self._visit_column_change, | ||||
start_alter=False) | ||||
def _visit_column_change(self, table, column, delta): | ||||
# Oracle cannot drop a default once created, but it can set it | ||||
# to null. We'll do that if default=None | ||||
# http://forums.oracle.com/forums/message.jspa?messageID=1273234#1273234 | ||||
dropdefault_hack = (column.server_default is None \ | ||||
and 'server_default' in delta.keys()) | ||||
# Oracle apparently doesn't like it when we say "not null" if | ||||
# the column's already not null. Fudge it, so we don't need a | ||||
# new function | ||||
notnull_hack = ((not column.nullable) \ | ||||
and ('nullable' not in delta.keys())) | ||||
# We need to specify NULL if we're removing a NOT NULL | ||||
# constraint | ||||
null_hack = (column.nullable and ('nullable' in delta.keys())) | ||||
if dropdefault_hack: | ||||
column.server_default = sa.PassiveDefault(sa.sql.null()) | ||||
if notnull_hack: | ||||
column.nullable = True | ||||
colspec = self.get_column_specification(column, | ||||
override_nullable=null_hack) | ||||
if null_hack: | ||||
colspec += ' NULL' | ||||
if notnull_hack: | ||||
column.nullable = False | ||||
if dropdefault_hack: | ||||
column.server_default = None | ||||
self.start_alter_table(table) | ||||
self.append("MODIFY (") | ||||
self.append(colspec) | ||||
self.append(")") | ||||
class OracleConstraintCommon(object): | ||||
def get_constraint_name(self, cons): | ||||
# Oracle constraints can't guess their name like other DBs | ||||
if not cons.name: | ||||
raise exceptions.NotSupportedError( | ||||
"Oracle constraint names must be explicitly stated") | ||||
return cons.name | ||||
class OracleConstraintGenerator(OracleConstraintCommon, | ||||
ansisql.ANSIConstraintGenerator): | ||||
pass | ||||
class OracleConstraintDropper(OracleConstraintCommon, | ||||
ansisql.ANSIConstraintDropper): | ||||
pass | ||||
class OracleDialect(ansisql.ANSIDialect): | ||||
columngenerator = OracleColumnGenerator | ||||
columndropper = OracleColumnDropper | ||||
schemachanger = OracleSchemaChanger | ||||
constraintgenerator = OracleConstraintGenerator | ||||
constraintdropper = OracleConstraintDropper | ||||