Flask + SQLAlchemy [ Determine Success of Commit ]

Question

I have a view in flask that I want to use to display success when an object from a POST request is successfully committed. In the controller, I have ``` us = User(data_that_is_not_valid) db_session.add(us) db_session.commit() ``` As of now, db_commit() throws an exception when the object can't be committed. Is there a more friendly way that just returns true or false to specify whether the object has been added to the database without throwing an error? EDIT: Added copy of exception ``` Traceback (most recent call last): File "", line 1, in File "/usr/local/lib/python2.7/dist-packages/SQLAlchemy-0.8.0-py2.7-linux-x86_64.egg/sqlalchemy/orm/scoping.py", line 149, in do return getattr(self.registry(), name)(*args, **kwargs) File "/usr/local/lib/python2.7/dist-packages/SQLAlchemy-0.8.0-py2.7-linux-x86_64.egg/sqlalchemy/orm/session.py", line 719, in commit self.transaction.commit() File "/usr/local/lib/python2.7/dist-packages/SQLAlchemy-0.8.0-py2.7-linux-x86_64.egg/sqlalche…

Accepted Answer

Your data should be prepared anyway. But this case is not data format case And exception is always good, you just need to catch and use them

You should consider exception as returned False, also you should log the reason for fail for later solving of problem

```
failed=False
try:
   db_session.commit()
except Exception as e:
   #log your exception in the way you want -> log to file, log as error with default logging, send by email. It's upon you
   db_session.rollback()
   db_session.flush() # for resetting non-commited .add()
   failed=True
#some use of failed var, specific for your case if you need it
```

For better understanding of exceptions: Exceptions python docs As for your specific exception looks like autocommit is your issue. Or not commited some previous SQL operation: Sqlalchemy docs

Flask + SQLAlchemy [ Determine Success of Commit ]

Solution

Problem