SQLAlchemy.declarative和延迟列加载

Question

是否可以在SQLAlchemy中指定一些要延迟加载的列？我使用sqlalchemy.ext.declarative模块来定义我的映射,例如:

from sqlalchemy.ext.declarative import declarative_base

Base = declarative_base()

class SomeClass(Base):
    __tablename__ = 'some_table'
    id = Column(Integer, primary_key=True)
    name =  Column(String(50))

我希望例如列名称是延迟加载的,我该如何实现？

谢谢你

Answer 1

只需添加deferred()列声明:

class SomeClass(Base):
    __tablename__ = 'some_table'
    id = Column(Integer, primary_key=True)
    name =  deferred(Column(String(50)))