> On Wed, Mar 11, 2009 at 10:31 AM, Madhusudan C.S <madhusuda...@gmail.com>wrote:

>> Hi all,
>>      I wanted to fix this bug. I just went through the code to see what
>> was happening. For the same sample code given in the ticket, these were my
>> findings:

>> The schema generated looks like this and there is no issue with it:
>> CREATE TABLE "testapp_childmodel" (
>>     "parentmodel_ptr_id" integer NOT NULL PRIMARY KEY REFERENCES
>> "testapp_parentmodel" ("id"),
>>     "text" text NOT NULL
>> );
>> CREATE TABLE "testapp_parentmodel" (
>>     "id" integer NOT NULL PRIMARY KEY,
>>     "slug" varchar(50) NOT NULL
>> );
>> CREATE TABLE "testapp_parentmodel_links" (
>>     "id" integer NOT NULL PRIMARY KEY,
>>     "from_parentmodel_id" integer NOT NULL REFERENCES
>> "testapp_parentmodel" ("id"),
>>     "to_parentmodel_id" integer NOT NULL REFERENCES "testapp_parentmodel"
>> ("id"),
>>     UNIQUE ("from_parentmodel_id", "to_parentmodel_id")
>> );

>> CREATE INDEX "testapp_parentmodel_slug" ON "testapp_parentmodel" ("slug");

>> I inserted test1, test2 and test3(all names being values of slug field) to
>> ParentModel and linked test1 and test3 to test2 through links field. There
>> seems to be no issues. Then I inserted testc1, testc2 and testc3 to
>> ChildModel and linked testc2 and testc3 to testc1 through inherited links
>> field. Now I can see only to links, i.e
>> I get these results in the interactive interpreter:

>> >>> from dummy.testapp.models import ParentModel, ChildModel
>> >>> c1 = ChildModel.objects.get(slug='testc1')
>> >>> c2 = ChildModel.objects.get(slug='testc2')
>> >>> c3 = ChildModel.objects.get(slug='testc3')
>> >>> c1.links.all()
>> []
>> >>> c2.links.all()
>> [<ParentModel: testc1>]
>> >>> c3.links.all()
>> [<ParentModel: testc1>]

>> This means only to links are being queried and not from links for the
>> inherited model. I just saw how the queries are working and these are the
>> queries constructed for c1, c2 and c3 respectively.

>> SELECT "testapp_parentmodel"."id", "testapp_parentmodel"."slug" FROM
>> "testapp_parentmodel" INNER JOIN "testapp_parentmodel_links" ON
>> ("testapp_parentmodel"."id" =
>> "testapp_parentmodel_links"."to_parentmodel_id") WHERE
>> "testapp_parentmodel_links"."from_parentmodel_id" = 4  LIMIT 21

>> SELECT "testapp_parentmodel"."id", "testapp_parentmodel"."slug" FROM
>> "testapp_parentmodel" INNER JOIN "testapp_parentmodel_links" ON
>> ("testapp_parentmodel"."id" =
>> "testapp_parentmodel_links"."to_parentmodel_id") WHERE
>> "testapp_parentmodel_links"."from_parentmodel_id" = 5  LIMIT 21

>> SELECT "testapp_parentmodel"."id", "testapp_parentmodel"."slug" FROM
>> "testapp_parentmodel" INNER JOIN "testapp_parentmodel_links" ON
>> ("testapp_parentmodel"."id" =
>> "testapp_parentmodel_links"."to_parentmodel_id") WHERE
>> "testapp_parentmodel_links"."from_parentmodel_id" = 6  LIMIT 21

>> From what I see the queries must be actually UNION of two queries which
>> fetch data both from, "from" and "to" fields in the
>> "testapp_parentmodel_links" table.It should look some thing like this, from
>> what I have understood:

>> SELECT "testapp_parentmodel"."id", "testapp_parentmodel"."slug" FROM
>> "testapp_parentmodel" INNER JOIN "testapp_parentmodel_links" ON
>> ("testapp_parentmodel"."id" =
>> "testapp_parentmodel_links"."to_parentmodel_id") WHERE
>> "testapp_parentmodel_links"."from_parentmodel_id" = 4  LIMIT 21
>> UNION
>> SELECT "testapp_parentmodel"."id", "testapp_parentmodel"."slug" FROM
>> "testapp_parentmodel" INNER JOIN "testapp_parentmodel_links" ON
>> ("testapp_parentmodel"."id" =
>> "testapp_parentmodel_links"."from_parentmodel_id") WHERE
>> "testapp_parentmodel_links"."to_parentmodel_id" = 4  LIMIT 21

>> Is this an elegant approach? If so can some one help me implement this? I
>> went through the code of QuerySet, Manager classes and other parts of
>> django.db.models. How to go about from here? I am very keen on fixing this
>> issue. Kindly help me.

>> --
>> Thanks and regards,
>>  Madhusudan.C.S

>> Blogs at: www.madhusudancs.info
>> Official Email ID: madhusu...@madhusudancs.info

>> P.S: I am really sorry if the text is not wrapped. I am still not
>> understanding how wrapping works here. Will correct it from next mail. Hope
>> Auto text wrapping works.

> This looks like it may just be a symptom of
> http://code.djangoproject.com/ticket/10237 if I'm reading htis correctly.

> The problem looks very similar. I applied the patch and tried out. But it