Question

Man am passing these values from the function to the db model as :

function definition :

def send_as_notification_to(person , link_id , unique_content , which_app, notification_type ):

        nc = NotificationContent.objects.create( link_id = link_id , unique_content = str(unique_content))
        app_obj = MetaAppNames.objects.create(name = which_app)
        nt = NotificationType.objects.create( type = notification_type , app = app_obj) 
        notification = Notification(person = person)
        notification.content = nc
        notification.notification_type = nt
        notification.save()
        nc.save()
        app_obj.save()
        nt.save()

Calling view :

def crave_form(request):
    if request.method == 'POST':
        form = IcraveForm(request.POST)
        if form.is_valid():
            crave = form.save(commit = False)
            crave.person = request.user
            send_as_notification_to('admin' ,crave.id , crave.person , 'icrave' , 'crave' )
            crave.save()
    else:
        form = IcraveForm()
    return render(request, 'icrave/form.html', { 'form' : form})

but it’s giving me error as :

notification_notificationcontent.link_id may not be NULL

Traceback ::

Environment:


Request Method: POST
Request URL: http://localhost:8000/icrave/create/

Django Version: 1.3
Python Version: 2.7.1
Installed Applications:
['django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.sites',
 'django.contrib.messages',
 'django.contrib.comments',
 'ec.kiosk',
 'ec.chakra',
 'ec.ajax',
 'ec.broadcast',
 'ec.connect',
 'ec.seek',
 'ec.feed',
 'ec.ec_model',
 'ec.info',
 'ec.domains',
 'ec.souk',
 'ec.meta',
 'ec.shastra',
 'ec.chat',
 'ec.log',
 'ec.icrave',
 'ec.notification',
 'doj',
 'django.contrib.admin']
Installed Middleware:
('django.middleware.common.CommonMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware')


Traceback:
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
  111.                         response = callback(request, *callback_args, **callback_kwargs)
File "/Volumes/Disk2/workspace/ec/ec/icrave/views.py" in crave_form
  15.             send_as_notification_to('admin' ,crave.id , crave.person , 'icrave' , 'crave' )
File "/Volumes/Disk2/workspace/ec/ec/notification/api.py" in send_as_notification_to
  6.         nc = NotificationContent.objects.create( link_id = link_id , unique_content = str(unique_content))
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/manager.py" in create
  138.         return self.get_query_set().create(**kwargs)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/query.py" in create
  360.         obj.save(force_insert=True, using=self.db)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/base.py" in save
  460.         self.save_base(using=using, force_insert=force_insert, force_update=force_update)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/base.py" in save_base
  553.                     result = manager._insert(values, return_id=update_pk, using=using)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/manager.py" in _insert
  195.         return insert_query(self.model, values, **kwargs)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/query.py" in insert_query
  1436.     return query.get_compiler(using=using).execute_sql(return_id)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/sql/compiler.py" in execute_sql
  791.         cursor = super(SQLInsertCompiler, self).execute_sql(None)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/sql/compiler.py" in execute_sql
  735.         cursor.execute(sql, params)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/backends/util.py" in execute
  34.             return self.cursor.execute(sql, params)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/backends/sqlite3/base.py" in execute
  234.             return Database.Cursor.execute(self, query, params)

Exception Type: IntegrityError at /icrave/create/
Exception Value: notification_notificationcontent.link_id may not be NULL

Answer 1

When you call your function, you haven’t committed your object (crave) to the database. If it’s got a database-generated identifier for the id property, this will still be null. And it’s this id property value that it’s trying to use for the link_id that it is complaining about.

You need to either stop specifying commit=False, or you need to call crave.save, before you call your function.