SQLAlchemy新手在这里.
我正在尝试定义一个表示表数据子集的模型子类.具体来说,我希望子类映射给定ID的最新行.
例如,假设我有以下模型:
class AddressHistory(Base):
__table__ = 'address_table'
date = Column(Date, index=True, nullable=False)
id = Column(BigInteger, primary_key=True)
street = Column(String(2000))
city = Column(String(2000))
state = Column(String(2000))
zip = Column(Integer)
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我想要做的是定义这个模型的子类,它代表给定id的最新地址记录:
class MostRecentAddress(Address):
“””
Represents a row in AddressHistory with the most recent date for a given id.
”””
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是否有某种子查询我可以传递给mapper_args?或者有没有办法将表定义为select语句?