This page is going to be a collection of common issues Django MongoDB Engine users faced. Please help grow this collection – tell us about your troubles!

SITE_ID issues

AutoField (default primary key) values must be strings representing an ObjectId on MongoDB (got u'1' instead). Please make sure your SITE_ID contains a valid ObjectId string.

This means that your SITE_ID setting (What’s SITE_ID?!) is incorrect – it is set to “1” but the site object that has automatically been created has an ObjectId primary key.

If you add 'django_mongodb_engine' to your list of INSTALLED_APPS, you can use the tellsiteid command to get the default site’s ObjectId and update your SITE_ID setting accordingly:

$ ./ tellsiteid
The default site's ID is u'deafbeefdeadbeef00000000'. To use the sites framework, add this line to

Creating/editing user in admin causes DatabaseError

DatabaseError at /admin/auth/user/deafbeefdeadbeef00000000/
[...] This query is not supported by the database.

This happens because Django tries to execute JOINs in order to display a list of groups/permissions in the user edit form.

To workaround this problem, add 'djangotoolbox' to your INSTALLED_APPS which makes the Django admin skip the groups and permissions widgets.

No form field implemented for <class ‘djangotoolbox.fields.ListField’>