id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
8740	save(force_update=True) should raise a consistent exception when update is not possible	Richard Davies <richard.davies@…>	nobody	"At present save(force_update=True) raises different exceptions according to database backend when update is not possible. These should be unified so that calling code is not specific to the database backend, rather like IntegrityError is already. They could be unified onto IntegrityError itself or a different new error.

I attach a patch which adds an extra test, regressiontests/save_force_update. This test assumes that save(force_update=True) would raise IntegrityError. In the trace below you can see that different database backends actually each fail with different exceptions.


{{{
$ ./runtests.py --settings=sqlite save_force_update
======================================================================
FAIL: Doctest: regressiontests.save_force_update.models.__test__.API_TESTS
----------------------------------------------------------------------
Traceback (most recent call last):
  File ""/home/elastic/django-dev/trunk/django/test/_doctest.py"", line 2180, in runTest
    raise self.failureException(self.format_failure(new.getvalue()))
AssertionError: Failed doctest test for regressiontests.save_force_update.models.__test__.API_TESTS
  File ""/home/elastic/django-dev/trunk/tests/regressiontests/save_force_update/models.py"", line unknown line number, in API_TESTS

----------------------------------------------------------------------
File ""/home/elastic/django-dev/trunk/tests/regressiontests/save_force_update/models.py"", line ?, in regressiontests.save_force_update.models.__test__.API_TESTS
Failed example:
    try:
       m = ManualPrimaryKeyTest(id=2, data='Different')
       m.save(force_update=True)
    except Exception, e:
       if isinstance(e, IntegrityError):
           print ""Pass""
       else:
           print ""Fail with %s"" % type(e)
Expected:
    Pass
Got:
    Fail with <class 'sqlite3.DatabaseError'>


----------------------------------------------------------------------
Ran 1 test in 0.012s

FAILED (failures=1)



$ ./runtests.py --settings=postgresql_psycopg2 save_force_update
======================================================================
FAIL: Doctest: regressiontests.save_force_update.models.__test__.API_TESTS
----------------------------------------------------------------------
Traceback (most recent call last):
  File ""/home/elastic/django-dev/trunk/django/test/_doctest.py"", line 2180, in runTest
    raise self.failureException(self.format_failure(new.getvalue()))
AssertionError: Failed doctest test for regressiontests.save_force_update.models.__test__.API_TESTS
  File ""/home/elastic/django-dev/trunk/tests/regressiontests/save_force_update/models.py"", line unknown line number, in API_TESTS

----------------------------------------------------------------------
File ""/home/elastic/django-dev/trunk/tests/regressiontests/save_force_update/models.py"", line ?, in regressiontests.save_force_update.models.__test__.API_TESTS
Failed example:
    try:
       m = ManualPrimaryKeyTest(id=2, data='Different')
       m.save(force_update=True)
    except Exception, e:
       if isinstance(e, IntegrityError):
           print ""Pass""
       else:
           print ""Fail with %s"" % type(e)
Expected:
    Pass
Got:
    Fail with <class 'psycopg2.DatabaseError'>


----------------------------------------------------------------------
Ran 1 test in 0.067s

FAILED (failures=1)
}}}"	Bug	closed	Database layer (models, ORM)	dev	Normal	invalid		richard.davies@…	Accepted	0	0	0	0	0	0