Hi Gilad, The `parent_link` option can only be used if the model the o2o field is pointing to is a direct base of the model it's attached to. From what I understand `select_related` simply ignores `parent_link` fields since it assumes it's pointing to a MTI parent table which are JOINed by default (unless values() and friends are involved).
Django should warn you about this. Please file a new bug ticket <https://code.djangoproject.com/newticket> so we don't loose track of this issue. Thanks! Simon Le samedi 14 novembre 2015 08:03:56 UTC-5, Gilad a écrit : > > Hi, > Using Django 1.8.3, I have 2 models, both unmanaged (remote DB managed by > another system), with something similar to that: > > class Parent(Model): > ... some fields... > > class Child(Model): > id = OneToOneField(primary_key=True, parent_link=True) > ... some other fields ... > > Notes: > > 1. Parent is not abstract. > 2. Each of the models have their own real tables. > 3. Not using model inheritance because I want the parent_link field to > be called "id" (as the db column), and Django doesn't allow hiding fields > (with the same name). > > Given all that, using select_related('id') in a Child QuerySet doesn't > work (no exception but the Parent fields aren't fetched in the same DB > query). > In order to workaround the issue, I removed the parent_link attribute > (note that as the tables are unmanaged, this attribute, and others, exist > merely as documentation, so I can remove it). > Without the parent_link attribute, the Child fields are indeed fetched in > the same DB query, as expected from select_related(). > > Is it a bug in Django or something I'm missing? > -- You received this message because you are subscribed to the Google Groups "Django users" 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]. Visit this group at http://groups.google.com/group/django-users. To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/3295081a-19f9-4607-b883-55ed0714ac68%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
