我在每个模型中都有字段created_by和updated_by。这些字段会自动填充sqlalchemy.event.listen(以前称为MapperExtension)。对于每个模型,我写: 所有模型的SQLAlchemy“event.listen”
event.listen(Equipment, 'before_insert', get_created_by_id)
event.listen(Equipment, 'before_update', get_updated_by_id)
当模型是大量的代码变得丑陋。是否可以将event.listen立即应用于所有模型或几个?
UPD:我想这样做:
import pylons
from sqlalchemy import event, sql
from sqlalchemy import Table, ForeignKey, Column
from sqlalchemy.databases import postgresql
from sqlalchemy.schema import UniqueConstraint, CheckConstraint
from sqlalchemy.types import String, Unicode, UnicodeText, Integer, DateTime,\
Boolean, Float
from sqlalchemy.orm import relation, backref, synonym, relationship
from sqlalchemy import func
from sqlalchemy import desc
from sqlalchemy.orm.exc import NoResultFound
from myapp.model.meta import Session as s
from myapp.model.meta import metadata, DeclarativeBase
from pylons import request
def created_by(mapper, connection, target):
identity = request.environ.get('repoze.who.identity')
if identity:
id = identity['user'].user_id
target.created_by = id
def updated_by(mapper, connection, target):
identity = request.environ.get('repoze.who.identity')
if identity:
id = identity['user'].user_id
target.updated_by = id
from sqlalchemy.ext.declarative import declared_attr
from sqlalchemy.ext.declarative import has_inherited_table
class TestMixin(DeclarativeBase):
__tablename__ = 'TestMixin'
id = Column(Integer, autoincrement=True, primary_key=True)
event.listen(TestMixin, 'before_insert', created_by)
event.listen(TestMixin, 'before_update', updated_by)
class MyClass(TestMixin):
__tablename__ = 'MyClass'
__mapper_args__ = {'concrete':True}
id = Column(Integer, autoincrement=True, primary_key=True)
created_by = Column(Integer, ForeignKey('user.user_id',
onupdate="cascade", ondelete="restrict"))
updated_by = Column(Integer, ForeignKey('user.user_id',
onupdate="cascade", ondelete="restrict"))
当我添加一个新的MyClass的对象我有CREATED_BY =无。如果我为MyClass创建event.listen一切正常。怎么了?
我在这里找到了答案http://stackoverflow.com/questions/12753450/ sqlalchemy-mixins-and-event-listener – uralbash 2014-04-16 14:09:25