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77 lines
2.4 KiB
77 lines
2.4 KiB
''' Database models and setup ''' |
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from sqlalchemy import engine_from_config |
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from sqlalchemy.orm import sessionmaker |
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from sqlalchemy.orm import configure_mappers |
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import zope.sqlalchemy |
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# import or define all models here to ensure they are attached to the |
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# Base.metadata prior to any initialization routines |
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from .user import User, Role # flake8: noqa |
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from .orders import Category, Consumable, Order, OrderStatus # flake8: noqa |
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# run configure_mappers after defining all of the models to ensure |
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# all relationships can be setup |
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configure_mappers() |
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def get_engine(settings, prefix='sqlalchemy.'): |
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''' returns a sqlalchemy engine from the application configuration ''' |
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return engine_from_config(settings, prefix) |
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def get_session_factory(engine): |
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''' returns a database session ''' |
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factory = sessionmaker() |
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factory.configure(bind=engine) |
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return factory |
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def get_tm_session(session_factory, transaction_manager): |
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''' Get a sqlalchemy.orm.Session instance backed by a transaction. |
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This function will hook the session to the transaction manager which |
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will take care of committing any changes. |
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- When using pyramid_tm it will automatically be committed or aborted |
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depending on whether an exception is raised. |
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- When using scripts you should wrap the session in a manager yourself. |
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For example:: |
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import transaction |
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engine = get_engine(settings) |
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session_factory = get_session_factory(engine) |
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with transaction.manager: |
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dbsession = get_tm_session(session_factory, transaction.manager) |
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''' |
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dbsession = session_factory() |
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zope.sqlalchemy.register( |
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dbsession, transaction_manager=transaction_manager) |
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return dbsession |
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def includeme(config): |
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''' |
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Initialize the model for a Pyramid app. |
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Activate this setup using ``config.include('ordr2.models')``. |
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''' |
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settings = config.get_settings() |
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# use pyramid_tm to hook the transaction lifecycle to the request |
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config.include('pyramid_tm') |
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session_factory = get_session_factory(get_engine(settings)) |
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config.registry['dbsession_factory'] = session_factory |
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# make request.dbsession available for use in Pyramid |
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config.add_request_method( |
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# r.tm is the transaction manager used by pyramid_tm |
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lambda r: get_tm_session(session_factory, r.tm), |
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'dbsession', |
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reify=True |
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)
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