How to check if user is already in user database?

[joulumaa]

Hi,
  
If  user = auth.authenticate(username,password) results None, I would like to create new user and login it.
But I cannot find a way to determine easily if it is was None because of 1) it was not in database or 2) it was in database but password was wrong
I addition to those it may have been inActive or without permission, but first thing to check would be to find if username is in user database.
Is there any fast way to check it?

-thanks for help

[Shazwi Suwandi]

Have you tried something like user = User.objects.get(username="username")

[joulumaa]

so, if it was not in database is result None, or some err or how to validate? sorry I am very beginner ;-)

then same problem with that permission, how to verify if reason for failing was that?

-thanks

[James Bennett]

This may be a good time to review Django's documentation on how to perform database queries:

https://docs.djangoproject.com/en/1.7/topics/db/queries/#retrieving-a-single-object-with-get

[Mark Furbee]

Yes, that link will cover the basics...

Here's a couple ways to find out if a query returns any records:

    User.objects.filter(username=username).exists()  # .exists() returns boolean if records are found.

    User.objects.filter(username=username).count() != 0  # .count() returns number of records in query.

    User.objects.filter(username=username).first() is not None # .first() returns the first record if there are matches, and None if there aren't

    

On Fri, Jan 16, 2015 at 9:11 AM, James Bennett <ubern...@gmail.com> wrote:

This may be a good time to review Django's documentation on how to perform database queries:

https://docs.djangoproject.com/en/1.7/topics/db/queries/#retrieving-a-single-object-with-get

--
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 django-users...@googlegroups.com.
To post to this group, send email to django...@googlegroups.com.
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/CAL13Cg8MaAhTh%2B%3DoGTJ75jeZVY8-gt_hMkUTjZxyLxFkQ%2Bx36Q%40mail.gmail.com.

For more options, visit https://groups.google.com/d/optout.

[Mark Furbee]

Also, you can do a try/catch, but I don't really like this method, personally:

    try:

        User.objects.get(username=username)

    except User.DoesNotExist:

        # user didn't exist in database.

[joulumaa]

Exception Type:	TypeError
Exception Value:	catching classes that do not inherit from BaseException is not allowed
Did not work.

Get might be faster than filter, but .exact() did not work either

-thanks

[joulumaa]

ah...not exact but exist()....