openmedialibrary_platform/Linux/lib/python2.7/site-packages/alembic/ddl/postgresql.py
2014-05-16 01:20:41 +02:00

43 lines
1.4 KiB
Python

import re
from sqlalchemy import types as sqltypes
from .base import compiles, alter_table, format_table_name, RenameTable
from .impl import DefaultImpl
class PostgresqlImpl(DefaultImpl):
__dialect__ = 'postgresql'
transactional_ddl = True
def compare_server_default(self, inspector_column,
metadata_column,
rendered_metadata_default,
rendered_inspector_default):
# don't do defaults for SERIAL columns
if metadata_column.primary_key and \
metadata_column is metadata_column.table._autoincrement_column:
return False
conn_col_default = rendered_inspector_default
if None in (conn_col_default, rendered_metadata_default):
return conn_col_default != rendered_metadata_default
if metadata_column.type._type_affinity is not sqltypes.String:
rendered_metadata_default = re.sub(r"^'|'$", "", rendered_metadata_default)
return not self.connection.scalar(
"SELECT %s = %s" % (
conn_col_default,
rendered_metadata_default
)
)
@compiles(RenameTable, "postgresql")
def visit_rename_table(element, compiler, **kw):
return "%s RENAME TO %s" % (
alter_table(compiler, element.table_name, element.schema),
format_table_name(compiler, element.new_table_name, None)
)