Question

I’m trying to use Django transactions on MySQL with the commit_on_success decorator. According to the documentation, “If the function raises an exception, though, Django will roll back the transaction.” However, this doesn’t seem to work for me:

>>> @transaction.commit_on_success
... def fails():
...     Site.objects.create(name="New Site", ip_address="127.0.0.1")
...     raise ValueError("oh noes!")
... 
>>> Site.objects.count()   
2
>>> fails()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python2.6/site-packages/django/db/transaction.py", line 240, in _commit_on_success
    res = func(*args, **kw)
  File "<stdin>", line 4, in fails
ValueError: oh noes!
>>> Site.objects.count()
3
>>>

I’m pretty sure that MySQL supports transactions; do I need to use a different table type or something?

Answer 1

From http://docs.djangoproject.com/en/dev/ref/databases/:

“The default engine is MyISAM [1]. The main drawback of MyISAM is that it doesn’t currently support transactions or foreign keys. On the plus side, it’s currently the only engine that supports full-text indexing and searching.

“The InnoDB engine is fully transactional and supports foreign key references.”