Option to leave off __exact

[Manuzhai]

Doing sites.get_object(id__exact = 1) seems kind of verbose if sites.get_object(id = 1) would convey the same meaning and be a little easier to read.

[Manuzhai]

Okay, so I meant

id__exact

[Adrian Holovaty]

My thoughts on this: Explicit is better than implicit.

[rmunn@…]

But not if what's implicit is blindingly obvious.

The option of idexact should be kept, but I can't conceive of any other meaning for polls.get_object(id=5) than id__exact=5. Beautiful is better than ugly. Simple is better than complex. Readability counts. I'll see your Zen and raise you two more. :-)

[rmunn@…]

Argh, should have put triple-braces around that id__exact. What I meant to say was:

The option of id__exact should be kept, but I can't conceive of any other meaning for polls.get_object(id=5) than id__exact=5.

Beautiful is better than ugly.
Simple is better than complex.
Readability counts.

I'll see your Zen quote and raise you two more. :-)

[rmunn@…]

Besides, look at how short the patch is!

Index: django/core/meta.py
===================================================================
--- django/core/meta.py	(revision 299)
+++ django/core/meta.py	(working copy)
@@ -1142,8 +1147,10 @@
             continue
         lookup_list = kwarg.split(LOOKUP_SEPARATOR)
         if len(lookup_list) == 1:
-            _throw_bad_kwarg_error(kwarg)
-        lookup_type = lookup_list.pop()
+            # polls.get_object(id=5) is shorthand for polls.get_object(id__exact=5)
+            lookup_type = 'exact'
+        else:
+            lookup_type = lookup_list.pop()
         current_opts = opts # We'll be overwriting this, so keep a reference to the original opts.
         current_table_alias = current_opts.db_table
         param_required = False

Isn't it the cutest patch you've ever seen? It followed me home, Mom, can I please apply it to the repository? :-)

On a serious note: this will only work for lookups that are one "level" of complexity deep, e.g. get_object(id=5). I thought about the possibility of doing choices.get_list(polls__sites__id=5) instead of choices.get_list(polls__sites__id__exact=5) and realized no, that wouldn't be a good idea. If you're writing out a relation of this much complexity, it's better to be explicit about the fact that you're doing an exact match. But in the vast majority of cases where you'd want to use the shorthand, you're doing something like get_object(id=5).

[Jacob]

See the discussion on this ticket here: ​http://loglibrary.com/show_page/view/179?Multiplier=3600&Interval=6&StartTime=1122065878 and the resulting proposal here: ​http://groups-beta.google.com/group/django-developers/browse_thread/thread/6eb17e5d996ed393/ab1cee3ad60980a7#ab1cee3ad60980a7

Basically: add a magic "pk=" keyword to lookups that would do a "primarykeyfieldexact=whatever" lookup for you.

[rmunn@…]

Here's a patch to use the magic "pk=(value)" syntax.

Index: django/core/meta.py
===================================================================
--- django/core/meta.py (revision 300)
+++ django/core/meta.py (working copy)
@@ -1142,7 +1147,12 @@
             continue
         lookup_list = kwarg.split(LOOKUP_SEPARATOR)
         if len(lookup_list) == 1:I tested against SQLite;
-            _throw_bad_kwarg_error(kwarg)
+            if kwarg == 'pk':
+                # "pk=value" is shorthand for "(primary key)__exact=value"
+                lookup_list = [opts.pk.name, 'exact']
+            else:
+                # Not shorthand, just a bad kwarg
+                _throw_bad_kwarg_error(kwarg)
         lookup_type = lookup_list.pop()
         current_opts = opts # We'll be overwriting this, so keep a reference to the original opts.
         current_table_alias = current_opts.db_table

Again, it would be possible to do this at deeper levels, but I think the risk of ambiguity isn't worth the effort saved. Besides, if you're going through one table to get to the next table, you probably don't have an id into the second table anyway.

[Clint Ecker <clintecker@…>]

I would like it if sites.get_object(1) would default to using the primary key. I personally think id= is a little verbose myself :)

[Adrian Holovaty]

(In [316]) Fixed #163 -- Added 'pk' database API option, which is a shorthand for (primary_key)exact

[(none)]

Milestone Version 1.0 deleted