= Django on Windows = (work in progress) [[TOC]] == Development == === Test suite failures === As of r8135 the test suite is showing the follwing platform-specific failures when run on Windows + Python 2.5.2: * On a test from {{{tests/regressiontests/queries/models.py}}} when using the sqlite3 Django DB backend. ==== tests/regressiontests/queries/models.py ==== This has been reported as ticket #7570. This test fails: {{{ #!python Bug #7087 -- dates with extra select columns >>> Item.objects.dates('created', 'day').extra(select={'a': 1}) [datetime.datetime(2007, 12, 19, 0, 0), datetime.datetime(2007, 12, 20, 0, 0)] }}} Error is: {{{ ====================================================================== FAIL: Doctest: regressiontests.queries.models.__test__.API_TESTS ---------------------------------------------------------------------- Traceback (most recent call last): File "C:\ramiro\django-trunk\django\test\_doctest.py", line 2180, in runTest raise self.failureException(self.format_failure(new.getvalue())) AssertionError: Failed doctest test for regressiontests.queries.models.__test__.API_TESTS File "C:\ramiro\django-trunk\tests\regressiontests\queries\models.py", line unknown line number, in API_TESTS ---------------------------------------------------------------------- File "C:\ramiro\django-trunk\tests\regressiontests\queries\models.py", line ?, in regressiontests.queries.models.__test__.API_TESTS Failed example: Item.objects.dates('created', 'day').extra(select={'a': 1}) Exception raised: Traceback (most recent call last): File "C:\ramiro\django-trunk\django\test\_doctest.py", line 1267, in __run compileflags, 1) in test.globs File "", line 1, in Item.objects.dates('created', 'day').extra(select={'a': 1}) File "c:\ramiro\django-trunk\django\db\models\query.py", line 129, in __repr__ return repr(list(self)) File "c:\ramiro\django-trunk\django\db\models\query.py", line 141, in __len__ self._result_cache.extend(list(self._iter)) File "c:\ramiro\django-trunk\django\db\models\sql\subqueries.py", line 351, in results_iter for rows in self.execute_sql(MULTI): File "c:\ramiro\django-trunk\django\db\models\sql\query.py", line 1607, in execute_sql cursor.execute(sql, params) File "c:\ramiro\django-trunk\django\db\backends\sqlite3\base.py", line 136, in execute return Database.Cursor.execute(self, query, params) OperationalError: ORDER BY terms must not be non-integer constants ---------------------------------------------------------------------- Ran 253 tests in 433.032s FAILED (failures=1) }}} A minimal models.py file that shows the problem (extracted from the above regression test): {{{ #!python """ >>> time1 = datetime.datetime(2007, 12, 19, 22, 25, 0) >>> time2 = datetime.datetime(2007, 12, 19, 21, 0, 0) >>> time3 = datetime.datetime(2007, 12, 20, 22, 25, 0) >>> time4 = datetime.datetime(2007, 12, 20, 21, 0, 0) >>> i1 = Item(name='one', created=time1, modified=time1) >>> i1.save() >>> i2 = Item(name='two', created=time2) >>> i2.save() >>> i3 = Item(name='three', created=time3) >>> i3.save() >>> i4 = Item(name='four', created=time4) >>> i4.save() >>> Item.objects.dates('created', 'day').extra(select={'a': 1}) [datetime.datetime(2007, 12, 19, 0, 0), datetime.datetime(2007, 12, 20, 0, 0)] """ from django.db import models import datetime class Item(models.Model): name = models.CharField(max_length=10) created = models.DateTimeField() modified = models.DateTimeField(blank=True, null=True) class Meta: ordering = ['name'] def __unicode__(self): return self.name }}} The SQL being generated by Django is correct: {{{ #!python >>> Item.objects.dates('created', 'day').extra(select={'a': 1}).query.as_sql() ('SELECT DISTINCT (1) AS "a", django_date_trunc("day", "sqlite3_dates_item"."created") FROM "sqlite3_dates_item" ORDER BY 1 ASC', ()) }}} Problem seems to be related to some bug in the version of pysqlite2 or sqlite3 (main suspect) included with the official Python 2.5.2 win32 installer (2.3.2 and 3.3.4 respectively): {{{ #!python Python 2.5.2 (r252:60911, Feb 21 2008, 13:11:45) [MSC v.1310 32 bit (Intel)] on win32 Type "help", "copyright", "credits" or "license" for more information. >>> from sqlite3 import dbapi2 >>> print dbapi2.version_info (2, 3, 2) >>> print dbapi2.sqlite_version_info (3, 3, 4) }}} The win32 installer for Python 2.5 ships the same combination of pysqlite/sqlite versions and exhibits the same problem. The tests were also run under some other Windows- and Linux-based scenarios. Summarizing: || '''Platform''' || '''Python version''' || '''pysqlite2 version''' || '''sqlite version''' || '''works?''' || '''Notes''' || || win32 || 2.4.4 || 2.3.0 (external) || 3.3.6 || YES || || || Debian Linux || 2.4.4 || 2.3.2 (external) || 3.3.8 || YES || || || win32 || 2.5 || 2.3.2 (built-in sqlite3)|| 3.3.4 || NO || || || Debian Linux || 2.5 || 2.3.2 (built-in sqlite3)|| 3.3.8 || YES || || || win32 || 2.5.2 || 2.3.2 (built-in sqlite3)|| 3.3.4 || NO || || || win32 || 2.5.2 || 2.4.1 (external) || 3.5.2 || YES || '''*''' || || Debian Linux || 2.5.2 || 2.3.2 (built-in sqlite3)|| 3.5.9 || YES || || As it can be seen, the test under Linux were always successful, this may be due to the fact that on these platforms the shared sqlite3 library being used by the pysqlite2 (Python 2.4) or sqlite3 (Python 2.5) Python modules is the system wide one and so it hasn't been frozen at 3.3.4. ===== Possible solution ===== As the table above shows, version 3.3.4 of sqlite seems to be affected by this bug whilst version 3.3.6 isn't (see http://sqlite.org/changes.html for possible hints). As sqlite/pysqlite development continues, the pysqlite project keeps publishing new win32 binary installers for Python 2.5. Latest as of June 29, 2008 is version 2.4.1 ({{{pysqlite-2.4.1.win32-py2.5.exe}}}) that uses sqlite version 3.5.2 (see entry marked with '''*''' in the table above.) ===== How does this affect Django ===== The problem doesn't lie within Django itself, but leads to ask oneself if the order being used by the sqlite3 backed to try loading the sqlite DB-API2 modules ({{{django/db/backends/sqlite3/base.py}}}) shouldn't be inverted: Try loading pysqlite2 first and if this fails then try loading sqlite3: {{{ #!diff --- base.py 2008-04-27 00:58:35.000000000 -0300 +++ base.py-proposed 2008-06-29 20:48:29.000000000 -0300 @@ -3,15 +3,16 @@ Python 2.3 and 2.4 require pysqlite2 (http://pysqlite.org/). -Python 2.5 and later use the sqlite3 module in the standard library. +Python 2.5 and later use pysqlite2 or the sqlite3 module in the standard +library. """ from django.db.backends import BaseDatabaseWrapper, BaseDatabaseFeatures, BaseDatabaseOperations, util try: try: - from sqlite3 import dbapi2 as Database - except ImportError: from pysqlite2 import dbapi2 as Database + except ImportError: + from sqlite3 import dbapi2 as Database except ImportError, e: import sys from django.core.exceptions import ImproperlyConfigured }}} Reasoning behind this is that this would allow the user to take advantage of newer pysqlite2/sqlite3 versions he/she may have installed even if using Python 2.5.x. This might be true and desirable regardless of platform. == Deployment == * WindowsInstall * wiki:django_apache_and_mod_wsgi * ServerArrangements