33 lines
989 B
Python
33 lines
989 B
Python
from datetime import datetime
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import sqlalchemy as sa
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class Timestamp(object):
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"""Adds `created` and `updated` columns to a derived declarative model.
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The `created` column is handled through a default and the `updated`
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column is handled through a `before_update` event that propagates
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for all derived declarative models.
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::
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import sqlalchemy as sa
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from sqlalchemy_utils import Timestamp
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class SomeModel(Base, Timestamp):
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__tablename__ = 'somemodel'
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id = sa.Column(sa.Integer, primary_key=True)
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"""
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created = sa.Column(sa.DateTime, default=datetime.utcnow, nullable=False)
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updated = sa.Column(sa.DateTime, default=datetime.utcnow, nullable=False)
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@sa.event.listens_for(Timestamp, 'before_update', propagate=True)
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def timestamp_before_update(mapper, connection, target):
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# When a model with a timestamp is updated; force update the updated
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# timestamp.
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target.updated = datetime.utcnow()
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