本文整理汇总了Python中mediadrop.model.meta.DBSession.begin_nested方法的典型用法代码示例。如果您正苦于以下问题：Python DBSession.begin_nested方法的具体用法？Python DBSession.begin_nested怎么用？Python DBSession.begin_nested使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类mediadrop.model.meta.DBSession的用法示例。
在下文中一共展示了DBSession.begin_nested方法的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Python代码示例。
示例1: insert_settings
# 需要导入模块: from mediadrop.model.meta import DBSession [as 别名]
# 或者: from mediadrop.model.meta.DBSession import begin_nested [as 别名]
def insert_settings(defaults):
"""Insert the given setting if they don't exist yet.
XXX: Does not include any support for MultiSetting. This approach
won't work for that. We'll need to use a migration script.
:type defaults: list
:param defaults: Key and value pairs
:rtype: list
:returns: Any settings that have just been created.
"""
inserted = []
try:
settings_query = DBSession.query(Setting.key)\
.filter(Setting.key.in_([key for key, value in defaults]))
existing_settings = set(x[0] for x in settings_query)
except ProgrammingError:
# If we are running paster setup-app on a fresh database with a
# plugin which tries to use this function every time the
# Environment.loaded event fires, the settings table will not
# exist and this exception will be thrown, but its safe to ignore.
# The settings will be created the next time the event fires,
# which will likely be the first time the app server starts up.
return inserted
for key, value in defaults:
if key in existing_settings:
continue
transaction = DBSession.begin_nested()
try:
s = Setting(key, value)
DBSession.add(s)
transaction.commit()
inserted.append(s)
except IntegrityError:
transaction.rollback()
if inserted:
DBSession.commit()
return inserted