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Django Queryset

Subject : it-skills

Instructions:

Answer 50 questions in 15 minutes.
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Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. Lookup type that corresponds to a boolean full-text search - taking advantage of full-text indexing. This is like contains but is significantly faster due to full-text indexing.
search
choices
week_day
istartswith

2. This field is added automatically - but this behavior can be overridden
Q()
id field
__unicode__()
DoesNotExist

3. Lookup type that returns results greater than or equal to a given value.
istartswith
filter(**kwargs)
primary_key
gte

4. Use this method to reverse the order in which a queryset's elements are returned. Calling this method a second time restores the ordering back to the normal direction.
iendswith
reverse()
in
order_by(*fields)

5. By default - results returned by a QuerySet are ordered by the ordering tuple given by the ordering option in the model's Meta. You can override this on a per-QuerySet basis by using the this method.
edit your settings file and change the INSTALLED_APPS setting to add the name of the module that contains your models.py.
Manager
when you add new apps to INSTALLED_APPS
order_by(*fields)

6. The first element in this iterable is the value that will be stored in the database - the second element will be displayed by the admin interface - or in a ModelChoiceField.
Meta class
choices tuple
__unicode__()
lte

7. Each one of these is a Python class that subclasses django.db.models.Model. Each attribute of one of these represents a database field.
using(alias)
iterator()
iteration
model

8. a QuerySet can be sliced - using Python's array-slicing syntax.
slicing
annotate(args - *kwargs)
MultipleObjectsReturned
values_list(*fields)

9. Performs an SQL update query for the specified fields - and returns the number of rows affected. This method is applied instantly and the only restriction on the QuerySet that is updated is that it can only update columns in the model's main table. F
update(**kwargs)
gte
Custom model methods
add()

10. Accomplish this by using the field name of related fields across models - separated by double underscores - until you get to the field you want. For example - to get all Entry objects with a Blog whose name is 'Beatles Blog': Entry.objects.filter(blo
Abstract base class
month
relationship spanning
Q(question__startswith='Who') | ~Q(pub_date__year=2005)

11. Returns a QuerySet that will automatically "follow" foreign-key relationships - selecting that additional related-object data when it executes its query. This is a performance booster which results in (sometimes much) larger queries but means later u
order_by(*fields)
latest(field_name=None)
select_related()
dates(field - kind - order='ASC')

12. Returns a new QuerySet that uses SELECT DISTINCT in its SQL query. This eliminates duplicate rows from the query results.
iterator()
delete()
delete()
distinct()

13. Defines a one-to-one relationship. You use it just like any other Field type: by including it as a class attribute of your model.
none()
Entry.objects.filter(pub_date__range=(start_date - end_date))
iregex
OneToOneField

14. Lookup type for date/datetime fields that finds an exact day match.
day
many-to-one relationship
__unicode__()
Q(question__istartswith='What')

15. Takes a list of primary-key values and returns a dictionary mapping each primary-key value to an instance of the object with the given ID.
evaluation
week_day
class attributes
in_bulk(id_list)

16. Extra text to be displayed under the field on the object's admin form to provide assistance to users. It's useful for documentation even if your object doesn't have an admin form.
help_text
choices
Meta class
lt

17. Lookup type that returns results greater than a given value.
gt
clear() method
evaluation
endswith

18. Returns a ValuesQuerySet -- a QuerySet that returns dictionaries when used as an iterable - rather than model-instance objects.
regex
values(*fields)
update(**kwargs)
values_list(*fields)

19. Sometimes - the Django query syntax by itself can't easily express a complex WHERE clause. For these edge cases - Django provides this QuerySet modifier -- a hook for injecting specific clauses into the SQL generated by a QuerySet.
exclude(**kwargs)
all()
extra(select=None - where=None - params=None - tables=None - order_by=None - select_params=None)
save()

20. Lookup type that yields an "exact" match. If you don't provide a lookup type -- that is - if your keyword argument doesn't contain a double underscore -- the lookup type is assumed to be of this sort.
exact
gte
Entry.objects.filter(id__in=[1 - 3 - 4])
Entry.objects.filter(pub_date__year=2007).update(headline='Everything is the same')

21. Takes the ouput of one filter and uses it as input for another filter. This works because a refinement of a QuerySet is itself a QuerySet.
delete()
filter chaining
F()
QuerySet

22. If this option is True - the field is allowed to be blank. Default is False.
none()
blank
Many-to-many relationship through an intermediate model
when you add new apps to INSTALLED_APPS

23. Lookup type that tests for inclusion in a case-sensitive fashion.
iteration
Proxy model
contains
select_related()

24. This method is more or less the opposite of defer(). You call it with the fields that should not be deferred when retrieving a model. If you have a model where almost all the fields need to be deferred - using this method to specify the complementary
only(*fields)
id field
iexact
Q(question__istartswith='What')

25. A manager method which returns a single object. If there are no results that match the query - this method will raise a DoesNotExist exception. If more than one item matches this query - the method will raise MultipleObjectsReturned.
get(**kwargs)
startswith
save()
delete()

26. If you are using this attribute on a ForeignKey or ManyToManyField - you must always specify a unique reverse name for the field.
gt
week_day
Entry.objects.filter(id__in=[1 - 3 - 4])
related_name

27. This model method is used for updating a ManyToManyField.
startswith
add()
update(**kwargs)
edit your settings file and change the INSTALLED_APPS setting to add the name of the module that contains your models.py.

28. In this case - an intermediate model can have multiple foreign keys to the source model. Here - two foreign keys to the same model are permitted - but they will be treated as the two (different) sides of the many-to-many relation.
gt
model
lte
Many-to-many relationship to self

29. A Q object that encapsulates queries for entries with a question value that starts with 'What' in a case-insensitive fashion.

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

30. Returns an integer representing the number of objects in the database matching the QuerySet. This never raises exceptions.
__unicode__()
select_related()
count()
exclude(**kwargs)

31. Can be used to remove all many-to-many relationships for an instance
lt
filter(**kwargs)
clear() method
none()

32. This model type is useful if you only want to modify the Python-level behavior of a model - without changing the models fields in any way. This creates a stand-in for the original model. You can create - delete and update instances of this new model
Meta class
Proxy model
help_text
DoesNotExist

33. This model method saves a model instance to the database. This method has no return value.
filter(**kwargs)
choices tuple
save()
Entry.objects.filter(pub_date__year=2005).delete()

34. This method immediately deletes the object and has no return value.
all()
Meta class
delete()
month

35. The database that will be used if this query is executed now
~
relationship spanning
model
db

36. This query deletes all Entry objects with a pub_date year of 2005.
filter(**kwargs)
save()
range
Entry.objects.filter(pub_date__year=2005).delete()

37. Performs an SQL delete query on all rows in the QuerySet. This method is applied instantly. You cannot call this method on a QuerySet that has had a slice taken or can otherwise no longer be filtered.
Custom model methods
delete()
distinct()
reverse name

38. True if the QuerySet has an order_by() clause or a default ordering on the model. False otherwise.
values(*fields)
ordered
latest(field_name=None)
Entry.objects.filter(pub_date__year=2007).update(headline='Everything is the same')

39. Evaluation happens upon use the "step" parameter of slice syntax - the first time you iterate over it - when pickling or caching results - upon calling repr() - upon calling len() - upon calling list() - upon calling bool()
values_list(*fields)
blank
Entry.objects.filter(id__in=[1 - 3 - 4])
evaluation

40. Lookup type that returns results less than a given value.
lt
add()
gt
create(**kwargs)

41. This class type is useful when you just want to use the parent class to hold information that you don't want to have to type out for each child model. This class isn't going to ever be used in isolation. When it is used as a base class for other mode
help_text
blank
Abstract base class
Entry.objects.filter(pub_date__range=(start_date - end_date))

42. The default for this is the name of the child class followed by '_set'.
pickling
MultipleObjectsReturned
reverse name
Manager methods

43. A convenience method for looking up an object with the given kwargs - creating one if necessary.
delete()
day
get_or_create(**kwargs)
save()

44. Operator for comparing two model instances for equality. Behind the scenes - it compares the primary key values of two models.
ForeignKey
get_absolute_url()
==
delete()

45. This is a criterion that narrow down a QuerySet based on given parameters.
filter
aggregate(args - *kwargs)
QuerySet
using(alias)

46. Specifies the model that will be used to govern the many-to-many relationship. You can then put extra fields on the intermediate model. The intermediate model is associated with the ManyToManyField using this to point to the model that will act as an
get_absolute_url()
delete()
Proxy model
through argument

47. A Manager method that returns a new QuerySet containing objects that match the given lookup parameters.
iterator()
pickling
related_name
filter(**kwargs)

48. This represents a collection of objects from your database. It can have zero - one or many filters.
QuerySet
exact
in
annotate(args - *kwargs)

49. Defined by a ManyToManyField. You use it just like any other Field type: by including it as a class attribute of your model.
values(*fields)
Q(question__startswith='Who') | ~Q(pub_date__year=2005)
count()
many-to-many relationship

50. This gives your model metadata.
Meta class
related_name
evaluation
all()