On Wed, Dec 7, 2011 at 12:56 PM, Jannis Leidel <lei...@gmail.com> wrote:
> > Ian, > > > This is a proposal to add support in Django for PyMySQL[1] as an > optional replacement for MySQLdb. > > > > I've been working with Vinay Sajip's Python 3-compatible branch; trying > to get MySQL support working, and I have had a great deal of success, using > PyMySQL as a back end, rather than MySQLdb. > > > > MySQLdb does not support Python3, and I haven't seen any indication > online that it will be supporting Python3 any time soon. > > That's not entirely true actually, I talked to Andy Dustman (MySQLdb's > author earlier this year while researching the bits needed for porting) and > he mentioned that several people ported it over the Python 3: > > - > http://sourceforge.net/projects/mysql-python/forums/forum/70460/topic/3831691 > - https://github.com/davispuh/MySQL-for-Python-3 > > Quoting him from his private reply: "I use 1.2.3 regularly with Django, so > if there's serious interest in a Python 3 version, I'll try to find the > time and energy to work on it again." > > As to which of those unofficial ports is the "correct" one, I can't help. > But it would certainly be helpful to get in touch with Andy before > dismissing MySQLdb altogether. > > That's great to hear, that there's still at least some motivation to move that project forward. My goal has been to help Vinay out with his Python 3 drive, by debugging the MySQL backend, and dropping this adapter in has been a way to at least get the rest of the backend code exercised. > > PyMySQL is a pure python implementation of PEP 249 for MySQL, and > supports Python 2.4 - 3.2, and MySQL 4.1 and higher. It is nearly a > plug-in-replacement for MySQLdb (although there are a few compatibility > issues that I have tried to take care of in Django backend code) > > > > My approach so far has been to patch django/db/backends/mysql: > > - Try to import MySQLdb, and then MySQLdb.converters and > MySQLdb.constants. > > - If that fails, try to import pymysql, and pymysql.converters and > pymysql.constants > > - Whichever succeeds, set a module-level variable 'backend' to > indicate the backend that we are using. > > > > - Patch the data-type conversions appropriately, depending on the > backend that was used. > > > > So far, that's it -- and I'm down to just a couple of unit test > failures, but those may even be Python3 issues; I haven't tracked them all > down yet. > > > > My questions, then: > > > > 1. Is PyMySQL appropriate for django-core, in the opinion of the core > devs? There isn't another stable Python 3-compatible mysql adapter, as far > as I know, and I don't think Django could move to Python 3 support without > at least the currently-supported databases. > > I think it's better to ask whether it's appropriate to switch the backend > library while doing the Python version jump. In my opinion it's not given > the stability MySQLdb has shown over the years. At least I'm not seeing > reasons to get rid of it. > Well, it sounds like moving Django to Python 3, even with MySQLdb support, would necessitate a simultaneous upgrade in MySQLdb anyway -- if there's no official version right now that support both 2 and 3, then we would have to upgrade both at the same time. Appreciated, though, that MySQLdb has a longer history, but it would still be at least some new code. And I wasn't trying to get rid of it, rather to support both of them at the same time, given that they have the same interface, and only a few internal differences, which can be smoothed over in module initialization. > > > 2. Is this the right approach? I know that in the past, we have had > multiple backends for PostgreSQL, in different modules under > django.db.backends, but in this case, the modules are almost 100% > compatible, except for the module names themselves, and the calling > conventions for the data conversions. It feels more like the situation with > JSON libraries, where we just load whichever one is available, and present > the same outward api to the developer. > > IMO it's not, database backends vary in the way to speak to the database, > so if -- and only if it's really needed to introduce another backend for > MySQL -- it should be independent from the current one. > > > 3. Code speaks, I know -- what's the best way to share this? I've sent > Vinay a patch, but that's for his Py3k branch, and might not get the > audience that something like this needs. I'm doing it for Py3k support, but > ideally it would work just as well under Python 2.x. Should I set up a > public repository somewhere, or just open a ticket and attach patches? > > I asked Martin von Löwis who maintains the Py3K branch in Django official > SVN repo to review Vinay's changes and merge them, as long as you manage to > get patches in line with their work I think we're fine. > Jannis > > -- > You received this message because you are subscribed to the Google Groups > "Django developers" group. > To post to this group, send email to django-developers@googlegroups.com. > To unsubscribe from this group, send email to > django-developers+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/django-developers?hl=en. > > -- Regards, Ian Clelland <clell...@gmail.com> -- You received this message because you are subscribed to the Google Groups "Django developers" group. To post to this group, send email to django-developers@googlegroups.com. 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