Select distinct values from a table field

Posted by alj on Stack Overflow See other posts from Stack Overflow or by alj
Published on 2010-03-17T22:56:31Z Indexed on 2010/03/17 23:01 UTC
Read the original article Hit count: 209

Filed under:

django

|

django-queryset

I'm struggling getting my head around the Django's ORM. What I want to do is get a list of distinct values within a field on my table .... the equivalent of one of the following:

SELECT DISTINCT myfieldname FROM mytable

(or alternatively)

SELECT myfieldname FROM mytable GROUP BY myfieldname

I'd at least like to do it the Django way before resorting to raw sql.

© Stack Overflow or respective owner

Related posts about django

Overriding the save() method of a model that uses django-mptt

as seen on Stack Overflow - Search for 'Stack Overflow'
I've been using django-mptt in my project for a while now, it's fabulous. Recently, I've found a need to override a model's save() method that uses mptt, and I'm getting an error when I try to save a new instance of that model: Exception Type: ValueError at /admin/scrivener/page/add/ Exception Value:… >>> More
Where is meta.local_fields set in django.db.models.base.py ?

as seen on Stack Overflow - Search for 'Stack Overflow'
I'm getting the error: Exception Value: (1110, "Column 'about' specified twice") As I was reviewing the Django error page, I noticed that the customizations the model User, seem to be appended to the List twice. This seems to be happening here in django/db/model/base.py in base_save(): values… >>> More
Deploying Django on EC2 using Bitnami Djangostack: WSGI script cannot be loadded

as seen on Stack Overflow - Search for 'Stack Overflow'
I've been struggling to deploy Django application on Amazon EC2 using Bitnami Djangostack for the last couple of days. When I go to http://dewey.io I see the default bitnami page (/opt/bitnami/apache2/htdocs/index.html), however, when I open http://dewey.io/portnoy, I get 'Internal Server Error'… >>> More
Internal Server Error with mod_wsgi [django] on windows xp

as seen on Stack Overflow - Search for 'Stack Overflow'
when i run development server it works very well, even an empty project runing in mod_wsgi i have no problem but when i want to put my own project i get an Internal Server Error (500) in my apache conf i put WSGIScriptAlias /codevents C:/django/apache/CODEvents.wsgi <Directory "C:/django/apache"> Order… >>> More
Internal Server Error with mod_wgsi [django] on windows xp

as seen on Stack Overflow - Search for 'Stack Overflow'
when i run development server it works very well, even an empty project runing in mod_wsgi i have no problem but when i want to put my own project i get an Internal Server Error (500) in my apache conf i put WSGIScriptAlias /codevents C:/django/apache/CODEvents.wsgi <Directory "C:/django/apache"> Order… >>> More

Related posts about django-queryset

Django queryset not returning the same values as the generated sql

as seen on Stack Overflow - Search for 'Stack Overflow'
Hello guys, I have the following queryset: subscribers = User.objects.values('email', 'username').filter( Q(subscription_settings__new_question='i') | Q(subscription_settings__new_question_watched_tags='i', marked_tags__id__in=question.tags.values('id'), tag_selections__reason='good')… >>> More
Django QuerySet filter method returns multiple entries for one record

as seen on Stack Overflow - Search for 'Stack Overflow'
Trying to retrieve blogs (see model description below) that contain entries satisfying some criteria: Blog.objects.filter(entries__title__contains='entry') The results is: [<Blog: blog1>, <Blog: blog1>] The same blog object is retrieved twice because of JOIN performed to filter objects… >>> More
Django QuerySet ordering by number of reverse ForeignKey matches

as seen on Stack Overflow - Search for 'Stack Overflow'
I have the following Django models: class Foo(models.Model): title = models.CharField(_(u'Title'), max_length=600) class Bar(models.Model): foo = models.ForeignKey(Foo) eg_id = models.PositiveIntegerField(_(u'Example ID'), default=0) I wish to return a list of Foo objects which have… >>> More
Matching blank entries in django queryset for optional field with corresponding ones in a required

as seen on Stack Overflow - Search for 'Stack Overflow'
I have a django queryset in my views whose values I pack before passing to my template. There is a problem when the queryset returns none since associated values are not unpacked. the quersyet is called comments. Here is my views.py def forums(request ): post_list = list(forum.objects.filter(child='0')&forum… >>> More
Django: QuerySet with objects where one time is earlier than another

as seen on Stack Overflow - Search for 'Stack Overflow'
I have a Django model TimeThingie with two TimeFields called t1 and t2. How do I get all TimeThingie objects where t1 < t2? >>> More