[pypy-dev] Running pysqlite on pypy

[Gerhard Häring]

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Antonio Cuni wrote:
> Hi Gerhard, hi all,
> 
> in the last days, we have been trying to run django on pypy, using the
> ctypes based implementation of pysqlite.
> 
> In doing this, we encountered a problem; we have exchanged a bit of
> private mails, so I try to sum up here:
> 
> This snippet explodes when run with pysqlite-ctypes, either on cpython
> or pypy-c:
> 
>>>>> from pysqlite2.dbapi2 import connect
>>>>> db = connect(':memory:')
>>>>> db.execute('BEGIN IMMEDIATE TRANSACTION')

That's illegal usage of pysqlite. In the very unlikely case that what
you really want to do is *not* use DB-API implicit transactions. You
have to switch to autocommit mode first:

set isolation_level=None; either the property on the connection object,
or directly in the connect() call. That was the root of the problem -
pysqlite's ctypes branch apparently will need to do a few more sanity
checks.

> [...] The double COMMIT is probably causing the problem; not sure if it's a
> bug in pysqlite-ctypes or an expected behavior.

Both, kind of ;-)

> Gerhard, what do you think about all of this? What's the best way to solve?

I just pushed an ad-hoc fix for this particular problem to the hg repo:

changeset:   328:c42db28b5031
branch:      ctypes
tag:         tip
parent:      317:89e6da6ea1cb
user:        Gerhard Haering <gh at ghaering.de>
date:        Sat May 17 03:19:37 2008 +0200
summary:     Quick fix: only use implicit transactions when autocommit
is off.

HTH & good night; just shout if there's anything else that needs fixing

- -- Gerhard
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