Wrong method in SQL query log

[Erki Bender]

When SQL query logging is enabled and you run a following:

n = now() - timedelta(days=30)
MyModel.objects.filter(my_date__lt=n).delete()

Query being logged is:

2017-04-05 11:41:22,192 DEBUG (0.019) QUERY = 'SELECT "MY_MODEL"."ID", "MY_MODEL"."MY_DATE" FROM "MY_MODEL" WHERE "MY_MODEL"."MY_DATE" < :arg0' - PARAMS = (Oracle_datetime(2017, 3, 6, 8, 41, 21, 913366),); args=(Oracle_datetime(2017, 3, 6, 8, 41, 21, 913366),)

The same behaviour happens with 1.10.* version of Django as well.

[kapil garg]

I don't see this. Here is the model i used and query i performed

class Test(models.Model):
    name = models.CharField(max_length=100, blank=True)

#shell
>>> Test.objects.filter(name__startswith='test').delete()
(0.000) BEGIN; args=None
(0.001) DELETE FROM "bug_test" WHERE "bug_test"."name" LIKE 'test%' ESCAPE '\'; args=('test%',)
(1, {'bug.Test': 1})

Is this bug related to some particular backend or does this bug also result in failure of the delete() method ?
Does your object get deleted or not ?

[Simon Charette]

This is caused by a combination of two things:

1. You have a pre_delete/post_delete signal registered for your MyModel or foreign keys pointing to it so Django doesn't perform a DELETE FROM right away and collects objects matching your filter() in memory to simulate ON DELETE.
2. No MyModel match your filter no the collection routine stops right away and doesn't both performing a DELETE FROM.