--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/pyams_alchemy/loader.py Wed Jul 01 10:16:20 2015 +0200
@@ -0,0 +1,56 @@
+#
+# Copyright (c) 2008-2015 Thierry Florac <tflorac AT ulthar.net>
+# All Rights Reserved.
+#
+# This software is subject to the provisions of the Zope Public License,
+# Version 2.1 (ZPL). A copy of the ZPL should accompany this distribution.
+# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
+# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
+# FOR A PARTICULAR PURPOSE.
+#
+
+__docformat__ = 'restructuredtext'
+
+
+# import standard library
+import logging
+logger = logging.getLogger('PyAMS (alchemy)')
+
+# import interfaces
+
+# import packages
+from pyams_alchemy.engine import get_user_session
+from sqlalchemy.orm.session import make_transient
+
+
+class DataLoader(object):
+ """SQLAlchemy data loader
+
+ This utility class is used to migrate entities from a given connection
+ to another one.
+ WARNING: actually, given entities must share the same schema name!!!
+ """
+
+ def __init__(self, source, target, entities):
+ """
+ Initialize data loader
+
+ :param source: name of registered source engine
+ :param target: name of registered target engine
+ :param entities: list of migrated entities
+ :return:
+ """
+ self.source_session = get_user_session(source)
+ self.target_session = get_user_session(target)
+ self.entities = entities
+
+ def run(self):
+ source = self.source_session
+ target = self.target_session
+ for entity in self.entities:
+ logger.info('Loading entity {0!r}'.format(entity))
+ for record in source.query(entity):
+ source.expunge(record)
+ make_transient(record)
+ target.add(record)