Opened 18 years ago
Closed 18 years ago
#4333 closed (invalid)
Filtering date gt in SQLite returns identical objects
Reported by: | Owned by: | Adrian Holovaty | |
---|---|---|---|
Component: | Database layer (models, ORM) | Version: | dev |
Severity: | Keywords: | sqlite date | |
Cc: | Triage Stage: | Unreviewed | |
Has patch: | no | Needs documentation: | no |
Needs tests: | no | Patch needs improvement: | no |
Easy pickings: | no | UI/UX: | no |
Description
I'm putting together a very simple blog app, and one feature I put in was to have a link to the next newer and older entries. Here's what (the relevant parts of) my model looks like:
class Entry(models.Model): when = models.DateField(core=True) def newer(self): set = Entry.objects.filter(blogger=self.blogger).filter(when__gt=self.when) try: return set[0] except IndexError: return None def older(self): set = Entry.objects.filter(blogger=self.blogger).filter(when__lt=self.when) try: return set[0] except IndexError: return None
I run my site using MySQL, and things work properly (ie, for the newest entry, newer returns None, etc). On my test environment, I'm using SQLite. Older works properly; however, when viewing the newest entry, newer returns itself.
Change History (3)
comment:1 by , 18 years ago
comment:3 by , 18 years ago
Resolution: | → invalid |
---|---|
Status: | new → closed |
Perhaps you are seeing this behavior because you are returning the first item of your set
QuerySet
, but the QuerySet
is not ordered. So you end up getting a random ordering of Entry
objects newer than the given Entry
object and returning the first item in that QuerySet
. This could lead to duplicate Entry
objects being returned since it's not ordered by when
date.
Have you tried the automatically-created
get_next_by_when
andget_previous_by_when
methods to see if they show the same behavior?