catching SQLAlchemy exceptions
PythonSqlalchemyExceptionPython Problem Overview
What is the upper level exception that I can catch SQLAlechmy exceptions with ?
>>> from sqlalchemy import exc
>>> dir(exc)
['ArgumentError', 'CircularDependencyError', 'CompileError', 'ConcurrentModificationError', 'DBAPIError', 'DataError', 'DatabaseError', 'DisconnectionError', 'FlushError', 'IdentifierError', 'IntegrityError', 'InterfaceError', 'InternalError', 'InvalidRequestError', 'NoReferenceError', 'NoReferencedColumnError', 'NoReferencedTableError', 'NoSuchColumnError', 'NoSuchTableError', 'NotSupportedError', 'OperationalError', 'ProgrammingError', 'SADeprecationWarning', 'SAPendingDeprecationWarning', 'SAWarning', 'SQLAlchemyError', 'SQLError', 'TimeoutError', 'UnboundExecutionError', 'UnmappedColumnError', '__builtins__', '__doc__', '__file__', '__name__', '__package__']
>>>
Python Solutions
Solution 1 - Python
To catch any exception SQLAlchemy throws:
from sqlalchemy import exc
db.add(user)
try:
db.commit()
except exc.SQLAlchemyError:
pass # do something intelligent here
See help(sqlalchemy.exc) and help(sqlalchemy.orm.exc) for a list of possible exceptions that sqlalchemy can raise.
Solution 2 - Python
From the source:
> The base exception class is
> SQLAlchemyError.
Solution 3 - Python
Depending on your version of SQLAlchemy (e.g. 1.0.4), you may need to do a little more to get to the base-SQLAlchemyError class:
from flask.ext.sqlalchemy import exc
exceptions = exc.sa_exc
try:
my_admin = user_models.User('space cadet', active=True)
db.session.add(my_admin)
db.session.commit()
except exceptions.SQLAlchemyError:
sys.exit("Encountered general SQLAlchemyError. Call an adult!")
this is because sqlalchemy.orm.exc now has the stanza:
"""SQLAlchemy ORM exceptions."""
from .. import exc as sa_exc, util