Manejo de errores de frasco
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27-10-2019 - |
Pregunta
Estoy tratando de detectar un error generado por Flask-Sqlalchemy. Desafortunadamente, mi código no puede manejar el error porque el depurador lo atrapa primero. Ocurre cuando trato de insertar un registro en una base de datos con un campo que se supone que es único pero que se duplica. ¿Hay alguna forma de evitar esto? Este es el rastreo.
sqlalchemy.exc.IntegrityError
IntegrityError: (IntegrityError) column username is not unique u'INSERT INTO user (username, password, karma) VALUES (?, ?, ?)' (u'Test', u'test', 0)
Traceback (most recent call last)
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File "/home/josh/Projects/masterpieces_of_code/env/lib/python2.6/site-packages/flask/app.py", line 889, in __call__
[Display the sourcecode for this frame] [Open an interactive python shell in this frame] return self.wsgi_app(environ, start_response)
*
File "/home/josh/Projects/masterpieces_of_code/env/lib/python2.6/site-packages/flask/app.py", line 879, in wsgi_app
[Display the sourcecode for this frame] [Open an interactive python shell in this frame] response = self.make_response(self.handle_exception(e))
*
File "/home/josh/Projects/masterpieces_of_code/env/lib/python2.6/site-packages/flask/app.py", line 876, in wsgi_app
[Display the sourcecode for this frame] [Open an interactive python shell in this frame] rv = self.dispatch_request()
*
File "/home/josh/Projects/masterpieces_of_code/env/lib/python2.6/site-packages/flask/app.py", line 695, in dispatch_request
[Display the sourcecode for this frame] [Open an interactive python shell in this frame] return self.view_functions[rule.endpoint](**req.view_args)
*
File "/home/josh/Projects/masterpieces_of_code/app.py", line 70, in create_user
[Display the sourcecode for this frame] [Open an interactive python shell in this frame] db.session.commit()
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File "/usr/share/pyshared/sqlalchemy/orm/scoping.py", line 129, in do
[Display the sourcecode for this frame] [Open an interactive python shell in this frame] return getattr(self.registry(), name)(*args, **kwargs)
*
File "/usr/share/pyshared/sqlalchemy/orm/session.py", line 653, in commit
[Display the sourcecode for this frame] [Open an interactive python shell in this frame] self.transaction.commit()
*
File "/usr/share/pyshared/sqlalchemy/orm/session.py", line 364, in commit
[Display the sourcecode for this frame] [Open an interactive python shell in this frame] self._prepare_impl()
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File "/usr/share/pyshared/sqlalchemy/orm/session.py", line 348, in _prepare_impl
[Display the sourcecode for this frame] [Open an interactive python shell in this frame] self.session.flush()
*
File "/usr/share/pyshared/sqlalchemy/orm/session.py", line 1346, in flush
[Display the sourcecode for this frame] [Open an interactive python shell in this frame] self._flush(objects)
*
File "/usr/share/pyshared/sqlalchemy/orm/session.py", line 1427, in _flush
[Display the sourcecode for this frame] [Open an interactive python shell in this frame] flush_context.execute()
*
File "/usr/share/pyshared/sqlalchemy/orm/unitofwork.py", line 299, in execute
[Display the sourcecode for this frame] [Open an interactive python shell in this frame] rec.execute(self)
*
File "/usr/share/pyshared/sqlalchemy/orm/unitofwork.py", line 443, in execute
[Display the sourcecode for this frame] [Open an interactive python shell in this frame] uow
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File "/usr/share/pyshared/sqlalchemy/orm/mapper.py", line 1833, in _save_obj
[Display the sourcecode for this frame] [Open an interactive python shell in this frame] execute(statement, params)
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File "/usr/share/pyshared/sqlalchemy/engine/base.py", line 1794, in execute
[Display the sourcecode for this frame] [Open an interactive python shell in this frame] object, *multiparams, **params)
*
File "/usr/share/pyshared/sqlalchemy/interfaces.py", line 149, in execute
[Display the sourcecode for this frame] [Open an interactive python shell in this frame] return execute(clauseelement, *multiparams, **params)
*
File "/usr/share/pyshared/sqlalchemy/engine/base.py", line 1157, in execute
[Display the sourcecode for this frame] [Open an interactive python shell in this frame] params)
*
File "/usr/share/pyshared/sqlalchemy/engine/base.py", line 1237, in _execute_clauseelement
[Display the sourcecode for this frame] [Open an interactive python shell in this frame] return self.__execute_context(context)
*
File "/usr/share/pyshared/sqlalchemy/engine/base.py", line 1268, in __execute_context
[Display the sourcecode for this frame] [Open an interactive python shell in this frame] context.parameters[0], context=context)
*
File "/usr/share/pyshared/sqlalchemy/engine/base.py", line 1806, in _cursor_execute
[Display the sourcecode for this frame] [Open an interactive python shell in this frame] cursor, statement, parameters, context, False)
*
File "/home/josh/Projects/masterpieces_of_code/env/lib/python2.6/site-packages/flaskext/sqlalchemy.py", line 115, in cursor_execute
[Display the sourcecode for this frame] [Open an interactive python shell in this frame] return execute(cursor, statement, parameters, context)
*
File "/usr/share/pyshared/sqlalchemy/engine/base.py", line 1367, in _cursor_execute
[Display the sourcecode for this frame] [Open an interactive python shell in this frame] context)
*
File "/usr/share/pyshared/sqlalchemy/engine/base.py", line 1360, in _cursor_execute
[Display the sourcecode for this frame] [Open an interactive python shell in this frame] context)
*
File "/usr/share/pyshared/sqlalchemy/engine/default.py", line 288, in do_execute
[Display the sourcecode for this frame] [Open an interactive python shell in this frame] cursor.execute(statement, parameters)
IntegrityError: (IntegrityError) column username is not unique u'INSERT INTO user (username, password, karma) VALUES (?, ?, ?)' (u'Test', u'test', 0)
This is the Copy/Paste friendly version of the traceback. You can also paste this traceback into the public lodgeit pastebin:
Traceback (most recent call last):
File "/home/josh/Projects/masterpieces_of_code/env/lib/python2.6/site-packages/flask/app.py", line 889, in __call__
return self.wsgi_app(environ, start_response)
File "/home/josh/Projects/masterpieces_of_code/env/lib/python2.6/site-packages/flask/app.py", line 879, in wsgi_app
response = self.make_response(self.handle_exception(e))
File "/home/josh/Projects/masterpieces_of_code/env/lib/python2.6/site-packages/flask/app.py", line 876, in wsgi_app
rv = self.dispatch_request()
File "/home/josh/Projects/masterpieces_of_code/env/lib/python2.6/site-packages/flask/app.py", line 695, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "/home/josh/Projects/masterpieces_of_code/app.py", line 70, in create_user
db.session.commit()
File "/usr/share/pyshared/sqlalchemy/orm/scoping.py", line 129, in do
return getattr(self.registry(), name)(*args, **kwargs)
File "/usr/share/pyshared/sqlalchemy/orm/session.py", line 653, in commit
self.transaction.commit()
File "/usr/share/pyshared/sqlalchemy/orm/session.py", line 364, in commit
self._prepare_impl()
File "/usr/share/pyshared/sqlalchemy/orm/session.py", line 348, in _prepare_impl
self.session.flush()
File "/usr/share/pyshared/sqlalchemy/orm/session.py", line 1346, in flush
self._flush(objects)
File "/usr/share/pyshared/sqlalchemy/orm/session.py", line 1427, in _flush
flush_context.execute()
File "/usr/share/pyshared/sqlalchemy/orm/unitofwork.py", line 299, in execute
rec.execute(self)
File "/usr/share/pyshared/sqlalchemy/orm/unitofwork.py", line 443, in execute
uow
File "/usr/share/pyshared/sqlalchemy/orm/mapper.py", line 1833, in _save_obj
execute(statement, params)
File "/usr/share/pyshared/sqlalchemy/engine/base.py", line 1794, in execute
object, *multiparams, **params)
File "/usr/share/pyshared/sqlalchemy/interfaces.py", line 149, in execute
return execute(clauseelement, *multiparams, **params)
File "/usr/share/pyshared/sqlalchemy/engine/base.py", line 1157, in execute
params)
File "/usr/share/pyshared/sqlalchemy/engine/base.py", line 1237, in _execute_clauseelement
return self.__execute_context(context)
File "/usr/share/pyshared/sqlalchemy/engine/base.py", line 1268, in __execute_context
context.parameters[0], context=context)
File "/usr/share/pyshared/sqlalchemy/engine/base.py", line 1806, in _cursor_execute
cursor, statement, parameters, context, False)
File "/home/josh/Projects/masterpieces_of_code/env/lib/python2.6/site-packages/flaskext/sqlalchemy.py", line 115, in cursor_execute
return execute(cursor, statement, parameters, context)
File "/usr/share/pyshared/sqlalchemy/engine/base.py", line 1367, in _cursor_execute
context)
File "/usr/share/pyshared/sqlalchemy/engine/base.py", line 1360, in _cursor_execute
context)
File "/usr/share/pyshared/sqlalchemy/engine/default.py", line 288, in do_execute
cursor.execute(statement, parameters)
IntegrityError: (IntegrityError) column username is not unique u'INSERT INTO user (username, password, karma) VALUES (?, ?, ?)' (u'Test', u'test', 0)
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Olvidé mencionar cómo reacciona Flask cuando intento manejar el error. Tengo algo relacionado con un global indefinido. Aquí está el rastreo para eso.
Traceback (most recent call last):
File "/home/josh/Projects/masterpieces_of_code/env/lib/python2.6/site-packages/flask/app.py", line 889, in __call__
return self.wsgi_app(environ, start_response)
File "/home/josh/Projects/masterpieces_of_code/env/lib/python2.6/site-packages/flask/app.py", line 879, in wsgi_app
response = self.make_response(self.handle_exception(e))
File "/home/josh/Projects/masterpieces_of_code/env/lib/python2.6/site-packages/flask/app.py", line 876, in wsgi_app
rv = self.dispatch_request()
File "/home/josh/Projects/masterpieces_of_code/env/lib/python2.6/site-packages/flask/app.py", line 695, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "/home/josh/Projects/masterpieces_of_code/app.py", line 72, in create_user
except(IntegrityError):
NameError: global name 'IntegrityError' is not defined
Solución
Necesitas poner un intento/atrapar en tu create_user
function (maestroPieces_of_code/app.py) en el bloque del código que hace el db.session.commit()
, y manejar la excepción allí.
Actualizar: Si está obteniendo un NameError
por IntegrityError
Entonces significa que es probable que te falta un
from sqlalchemy.exc import IntegrityError
en tus app.py
. Ese no es un mensaje de Flask, eso es Python que te cuenta sobre un nombre desconocido (debido a la importación faltante) ya que interpreta el código en app.py
.