#25591: Cannot QuerySet.update DateRangeField using F() expressions
----------------------------------+------------------------------------
Reporter: synotna | Owner: nobody
Type: New feature | Status: new
Component: contrib.postgres | Version: 1.8
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
----------------------------------+------------------------------------
Comment (by James Addison):
Using Python 3.5, Django 1.11. I'm not sure if I'm missing something
really simple, or this really isn't as straight-forward as one would
expect.
I want to migrate from 2 individual `FloatField`s to a single
`FloatRangeField`; with a model like this:
{{{
class MyModel(models.Model):
age_min = models.FloatField(null=True, blank=True)
age_max = models.FloatField(null=True, blank=True)
age_range = FloatRangeField(null=True, blank=True)
}}}
I'm unable to figure out how to use `.update()` with a custom `Func`:
{{{
class AgeRange(Func):
function = 'numrange'
}}}
From what I've read in this ticket, that `Func` ought to allow the
following to work:
{{{
MyModel.objects.all().update(age_range=AgeRange('age_min', 'age_max'))
}}}
However, I end up with the following traceback:
{{{
...
File "/home/ubuntu/.virtualenvs/myproject/lib/python3.5/site-
packages/django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
django.db.utils.ProgrammingError: function numrange(double precision,
double precision) does not exist
LINE 1: UPDATE "myapp_mymodel" SET "age_range" = numrange("act...
^
HINT: No function matches the given name and argument types. You might
need to add explicit type casts.
}}}
The pertinent fields in PostgreSQL:
{{{
Column | Type | Modifiers
-------------------------+--------------------------+----------------------
age_min | double precision |
age_max | double precision |
age_range | numrange |
}}}
Assuming that the PostgreSQL output `You might need to add explicit type
casts` is the real cause, how would I adapt my `Func` to address this?
Based on [https://www.postgresql.org/docs/9.6/static/rangetypes.html
#RANGETYPES-BUILTIN], `numrange` handles postgres `numeric` types, of
which `double precision` is one according to
[https://www.postgresql.org/docs/9.6/static/datatype-numeric.html].
--
Ticket URL: <https://code.djangoproject.com/ticket/25591#comment:5>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
--
You received this message because you are subscribed to the Google Groups
"Django updates" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/django-updates/065.61c2abad9092a610f78022f0a333509b%40djangoproject.com.
For more options, visit https://groups.google.com/d/optout.
