"SAWarning: transaction already deassociated from connection"是什么意思？

Question

SQLAlchemy事务如何从连接中解除关联？我该怎么做才能防止这种情况发生？

Answer 1

当SQLAlchemy试图回滚已回滚的事务或保存点时，会发出此警告。例如：

>>> import sqlalchemy as sa
>>> engine = sa.create_engine('sqlite:///', echo=True, future=True)
>>> with engine.connect() as conn:
...     with conn.begin() as txn:
...         txn.rollback()
...         txn.rollback()
... 

输出

2021-06-12 15:13:13,669 INFO sqlalchemy.engine.Engine BEGIN (implicit)
2021-06-12 15:13:13,669 INFO sqlalchemy.engine.Engine ROLLBACK
<stdin>:4: SAWarning: transaction already deassociated from connection

您可以在这里看到两个相关的单元测试。