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In Sqlalchemy, if i add an object using session.add() and flush it, session.query() does not give that object, why?

开发者 https://www.devze.com 2023-01-10 07:39 出处:网络
While using SQLAlchemy, i add a object to a session using session.add(objname), then either explicitly flush it using session.flush or enable autoflush=True while creating the engine itself.

While using SQLAlchemy, i add a object to a session using session.add(objname), then either explicitly flush it using session.flush or enable autoflush=True while creating the engine itself.

Now in the session, if want to return that object via session.query(classname).al开发者_如何学JAVAl(), i cannot retrieve it.

Why is that so? or is there a way in which query() can also retrieve flushed objects.


I can't reproduce your issue. Please provide sample code that I can run to reproduce it.

Here's code that does what you describe, but behaves as one would expect:

from sqlalchemy import Column, Integer, Unicode, create_engine
from sqlalchemy.orm import create_session
from sqlalchemy.ext.declarative import declarative_base

engine = create_engine('sqlite://')
Base = declarative_base(bind=engine)

class User(Base):
    __tablename__ = 'users'
    id = Column(Integer, primary_key=True)
    name = Column(Unicode(60))

Base.metadata.create_all()   

After that setup, Add a new user:

s = create_session(autocommit=False, autoflush=False)
u = User()
u.name = u'Cheezo'
s.add(u)
s.flush()

Then query it back:

>>> u2 = s.query(User).first()
>>> print u2.name
Cheezo
>>> u2 is u
True
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