林發送SQLAlchemy的對象槽淨到另一臺機器。首先,我將它序列化爲一個字符串,然後加密併發送。SQLAlchemy的串行合併
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker, scoped_session
from sqlalchemy.ext.serializer import loads, dumps
engine = create_engine(connection_str)
S = scoped_session(sessionmaker(bind=engine, expire_on_commit=False))
session = S()
data = session(MyObj).all()
serialized = pickle.dumps([dumps(d) for d in data])
crypted = crypt(serialized) #encrypting the serialized data
send(machine, crypted) #sending encripted data to 'machine'
,並在另一臺機器上: 我與序列化
encrypted = get_data()
serialized = decrypt(encrypted)
data = [loads(d, Base.metadata, S) for d in pickle.loads(serialized)]
for d in data:
session.merge(d)
session.commit()
但它拋出:(IntegrityError) node_type.id may not be NULL u'INSERT INTO myobj (col1, col2) VALUES (?, ?)' (None, None)
,當我嘗試打印data
它拋出:DetachedInstanceError Instance <MyObj at 0x24e0c70> is not bound to a Session; attribute refresh operation cannot proceed
或:ObjectDeletedError
是什麼問題?
這裏: How to create and restore a backup from SqlAlchemy?被告知session.merge()
會很好,但它沒有爲我工作。
確定現在它的作品!我用'pickle'(不是'sqlalchemy.ext.serializer'),但我的對象(表)必須有''__getstate__'方法__setstate__'這些方法都必須列初始化 – microo8
其實我看到你以前的評論,你說它沒有工作,並做了一些研究。如果您在調用'dumps()'之前從會話中清除對象,可能不需要'__getstate__'和'__setstate__'。我還沒有測試過。 –
清除不起作用 – microo8