python runtime_error ai_generated true

sqlalchemy.orm.exc.DetachedInstanceError: Instance is not bound to a Session; attribute refresh operation cannot proceed

ID: python/sqlalchemy-detached-instance-session-closed

Also available as: JSON · Markdown · 中文
80%Fix Rate
85%Confidence
0Evidence
2024-03-15First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
3.x active — — —

Root Cause

Attempting to access or refresh attributes of an ORM instance after its originating session has been closed or committed, leaving the instance in a detached state.

generic

中文

在原始会话已关闭或提交后尝试访问或刷新 ORM 实例的属性，导致实例处于分离状态。

Workarounds

  1. 85% success Merge the detached instance back into the session 
    Use session.merge() to re-attach the detached instance to a new session before accessing attributes.
  2. 90% success Refresh the instance before session closure 
    Ensure the session remains open and use session.refresh() before closing, or load needed attributes eagerly.

Dead Ends

Common approaches that don't work:

  1. Re-querying the object with session.query() without merging 70% fail

  2. Enabling autocommit on the session 60% fail