id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
7126	select_related(field) doesn't correctly SELECT GIS fields on MySQL/Oracle	benwalton@…	jbronn	"I'm not quite sure how to write a test, but I produced a simple script of what goes wrong.


I have a simple Item object which can optionally have a Location
{{{
from django.contrib.gis.db import models

class Location(models.Model):
    location = models.PointField()
    
    objects = models.GeoManager()

class Item(models.Model):
    name = models.CharField(max_length=10)
    location = models.ForeignKey(Location, null=True)
    
    objects = models.GeoManager()
}}}

Setup some data


{{{
from django.contrib.gis.geos import Point
from test.models import Location, Item

item = Item(name=""Place 1"")
item.save()
item = Item(name=""Place 2"")
location = Location(location=Point(1,1))
location.save()
item.location = location
item.save()
}}}


When I query the Items with select_related() everything works fine

{{{
>>> for i in Item.objects.select_related():
...     if i.location:
...         i.location.location
... 
<Point object at 0x21ad784>
>>> print connection.queries[-1]['sql']
SELECT `test_location`.`id`, AsText(`test_location`.`location`) FROM `test_location` WHERE `test_location`.`id` = 1 
}}}

When I specify select_related('location') to do a LEFT JOIN onto location, the query isn't formed properly

{{{
>>> for i in Item.objects.select_related('location'):
...     if i.location:
...         i.location.location
... 
Traceback (most recent call last):
  File ""<console>"", line 3, in <module>
  File ""/opt/local/lib/python2.5/site-packages/django/contrib/gis/db/models/proxy.py"", line 36, in __get__
    geom = self._klass(geom_value)
  File ""/opt/local/lib/python2.5/site-packages/django/contrib/gis/geos/base.py"", line 72, in __init__
    raise ValueError('String or unicode input unrecognized as WKT EWKT, and HEXEWKB.')
ValueError: String or unicode input unrecognized as WKT EWKT, and HEXEWKB.
>>> print connection.queries[-1]['sql']
SELECT `test_item`.`id`, `test_item`.`name`, `test_item`.`location_id`, `test_location`.`id`, `test_location`.`location` FROM `test_item` LEFT OUTER JOIN `test_location` ON (`test_item`.`location_id` = `test_location`.`id`)
}}}

I understand that this is a new feature rather than an old one that is broken. 


"		closed	GIS	gis		worksforme	select_related gis oracle mysql		Accepted	1	0	1	0	0	0