Opened 4 years ago
Closed 4 years ago
#32414 closed Uncategorized (duplicate)
Syntax Error when combining __in and F() in filter
Reported by: | Douglas Franklin | Owned by: | nobody |
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Component: | Database layer (models, ORM) | Version: | 3.1 |
Severity: | Normal | Keywords: | F() |
Cc: | Triage Stage: | Unreviewed | |
Has patch: | no | Needs documentation: | no |
Needs tests: | no | Patch needs improvement: | no |
Easy pickings: | no | UI/UX: | no |
Description (last modified by )
Similar to https://code.djangoproject.com/ticket/32151
I have a simple Google Calendar Events application. Profiles generate calendar tokens with GSuite Oauth (not shown) that are used to make CalendarEvents in my database (postgres:9.6). CalendarEvents queried via a particular CalendarToken have the token's profile on the model. See oversimplified example below:
class Profile(models.Model): name = models.CharField(max_length=32) class CalendarEvent(models.Model): profile = models.ForeignKey(Profile, on_delete=models.CASCADE) attendees = models.ManyToManyField(Profile, blank=True, related_name="attending_calendar_events")
I'm trying to annotate whether a profile is "attending" the event, by checking if the profile is in the attendees ManyToMany:
CalendarEvent.objects.annotate( is_attending=Case( When( profile__in=F('attendees'), then=Value(True) ), default=Value(False), output_field=models.BooleanField() ) )
Generates an invalid syntax error (replacing db name with {APP}):
ProgrammingError: syntax error at or near ""{APP}_calendarevent_attendees"" LINE 1: ...CASE WHEN ("{APP}_calendarevent"."profile_id" IN "{APP}_ca...
Change History (4)
comment:1 by , 4 years ago
Description: | modified (diff) |
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comment:3 by , 4 years ago
The latter worked perfectly. Really interesting. Thank you! I agree though, seems like a practical use-case to have the special case when get_prep_lookup
F
refers to a many-to-many.
The use of the through-table subquery is working for me, so it seems like an easy enough workaround.
Replying to Simon Charette:
Looks like you either want
attendees=F('profile')
orprofile__in=CalendarEvent.attendees.through.objects.filter(calendarevent=OuterRef('pk')).values('profile')
.
I guess we could raise a Python level error or adjust
RelatedIn.get_prep_lookup
special caseF
referring to many-to-many as well.
comment:4 by , 4 years ago
Resolution: | → duplicate |
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Status: | new → closed |
Duplicate of #31135. Please feel-free to add a comment to the original ticket.
Looks like you either want
attendees=F('profile')
orprofile__in=CalendarEvent.attendees.through.objects.filter(calendarevent=OuterRef('pk')).values('profile')
.I guess we could raise a Python level error or adjust
RelatedIn.get_prep_lookup
special caseF
referring to many-to-many as well.