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| author | Mike Bayer <mike_mp@zzzcomputing.com> | 2019-04-28 12:40:31 -0400 |
|---|---|---|
| committer | Mike Bayer <mike_mp@zzzcomputing.com> | 2019-04-28 12:44:00 -0400 |
| commit | 23a1c60982dc4799c76f0cec276a3bae8a24395b (patch) | |
| tree | a5e32ecc74a8d40ae4dd8049ef955bf9dbda9b68 /lib/sqlalchemy/orm/session.py | |
| parent | 2f55c844051d9fe8865576bd77107e94c6de16c1 (diff) | |
| download | sqlalchemy-23a1c60982dc4799c76f0cec276a3bae8a24395b.tar.gz | |
Warn on merge of already-pending object
A warning is now emitted for the case where a transient object is being
merged into the session with :meth:`.Session.merge` when that object is
already transient in the :class:`.Session`. This warns for the case where
the object would normally be double-inserted.
Fixes: #4647
Change-Id: Ie5223a59a2856664bf283017e962caf8c4230536
Diffstat (limited to 'lib/sqlalchemy/orm/session.py')
| -rw-r--r-- | lib/sqlalchemy/orm/session.py | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/lib/sqlalchemy/orm/session.py b/lib/sqlalchemy/orm/session.py index 0b1a3b101..eccd60fe2 100644 --- a/lib/sqlalchemy/orm/session.py +++ b/lib/sqlalchemy/orm/session.py @@ -2110,6 +2110,13 @@ class Session(_SessionClassMethods): key = state.key if key is None: + if state in self._new: + util.warn( + "Instance %s is already pending in this Session yet is " + "being merged again; this is probably not what you want " + "to do" % state_str(state) + ) + if not load: raise sa_exc.InvalidRequestError( "merge() with load=False option does not support " |