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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 for date/datetime fields that finds an exact year match. Takes a four-digit year.
class type
regex
range
year

2. This field is added automatically - but this behavior can be overridden
id field
MultipleObjectsReturned
iregex
gt

3. Lookup type for date/datetime fields that finds an exact day match.
exclude(**kwargs)
day
choices tuple
QuerySet

4. Lookup type that finds a case-insensitive regular expression match.
iregex
Manager
latest(field_name=None)
values_list(*fields)

5. Manager method used to retrieve every object in a model.
class attributes
filter(**kwargs)
aggregate(args - *kwargs)
all()

6. A manager method that returns a new QuerySet containing objects that do not match the given lookup parameters.
exclude(**kwargs)
MultipleObjectsReturned
&
none()

7. Lookup type that returns results greater than or equal to a given value.
OneToOneField
when you add new apps to INSTALLED_APPS
gte
Entry.objects.filter(pub_date__year=2005).delete()

8. 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.
Entry.objects.filter(id__in=[1 - 3 - 4])
intermediate models
class attributes
reverse()

9. This query deletes all Entry objects with a pub_date year of 2005.
filter(**kwargs)
Entry.objects.filter(pub_date__year=2005).delete()
MultipleObjectsReturned
Abstract base class

10. This is a criterion that narrow down a QuerySet based on given parameters.
annotate(args - *kwargs)
iendswith
week_day
filter

11. Returns True if the QuerySet contains any results - and False if not. This tries to perform the query in the simplest and fastest way possible - but it does execute nearly the same query. This means that calling this method on a queryset is faster th
values(*fields)
Field lookups
ordered
exists()

12. Fields are specified by these
exists()
intermediate models
class attributes
iregex

13. Lookup type that returns results that fall into an inclusive date range.
range
default
filter
class attributes

14. This query updates all the headlines with pub_date in 2007 to read 'Everything is the same'.

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

15. This object allows you to compare the value of a model field with another field on the same model. Django supports the use of addition - subtraction - multiplication - division and modulo arithmetic with these objects - both with constants and with o
one-to-one relationship
F()
annotate(args - *kwargs)
when you add new apps to INSTALLED_APPS

16. This model method saves a model instance to the database. This method has no return value.
relationship spanning
Entry.objects.filter(pub_date__year=2005).delete()
Entry.objects.all().update(n_pingbacks=F('n_pingbacks') + 1)
save()

17. If True - the table does not permit duplicate values for this field.
unique
dates(field - kind - order='ASC')
in_bulk(id_list)
Meta class

18. Keyword shortcut for looking up an object by primary key.
pk
exists()
default
Entry.objects.all().update(n_pingbacks=F('n_pingbacks') + 1)

19. This method returns tuples of values when iterated over. Each tuple contains the value from the respective field passed into the call to this method -- so the first item is the first field - etc.
Many-to-many relationship to self
get_or_create(**kwargs)
through argument
values_list(*fields)

20. Defined by django.db.models.ForeignKey. You use it just like any other Field type: by including it as a class attribute of your model.
Model metadata
many-to-one relationship
delete()
get_or_create(**kwargs)

21. Exception raised by get(**kwargs) if no items match the query.
DoesNotExist
regex
search
Field lookups

22. If you are using this attribute on a ForeignKey or ManyToManyField - you must always specify a unique reverse name for the field.
select_related()
only(*fields)
related_name
range

23. Lookup type for date/datetime fields that finds an exact month match. Takes an integer 1 (January) through 12
annotate(args - *kwargs)
iregex
db
month

24. 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(**kwargs)
save()
gte
through argument

25. Negation operator for Q objects.
Abstract base class
~
__unicode__()
dates(field - kind - order='ASC')

26. When to run syncdb
iregex
when you add new apps to INSTALLED_APPS
null
unique

27. 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()
month
evaluation
==
__unicode__()

28. If this option is True - the field is allowed to be blank. Default is False.
ManyToManyField
blank
select_related()
update(**kwargs)

29. 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
select_related()
month
ForeignKey
aggregate(args - *kwargs)

30. 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.
month
Restrictions on field names
exact
related_name

31. a QuerySet can be sliced - using Python's array-slicing syntax.
__unicode__()
startswith
slicing
Manager methods

32. Used to get a QuerySet for a model. This is called 'objects' by default.
&
values_list(*fields)
Manager
filter chaining

33. This sets a field to a particular value for all the objects in a QuerySet. You can only set non-relation fields and ForeignKey fields using this method.
choices
update()
Abstract base class
distinct()

34. This query finds all entries between a start date of start_date and an end date of end_date.
lt
Entry.objects.filter(pub_date__range=(start_date - end_date))
search
class type

35. Can be used to remove all many-to-many relationships for an instance
Model metadata
Many-to-many relationship to self
Abstract base class
clear() method

36. 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.
defer(*fields)
Abstract base class
clear() method
search

37. Returns a dictionary of aggregate values (averages - sums - etc) calculated over the QuerySet. Each argument to this method specifies a value that will be included in the dictionary that is returned.
aggregate(args - *kwargs)
Entry.objects.all().update(n_pingbacks=F('n_pingbacks') + 1)
filter(**kwargs)
many-to-one relationship

38. restrictions on ________: (1) Your intermediate model must contain one - and only one - foreign key to the target model. (2) Your intermediate model must contain one - and only one - foreign key to the source model. (3) When defining a many-to-many r
aggregate(args - *kwargs)
intermediate models
get_absolute_url()
in_bulk(id_list)

39. Lookup type that yields a case-insensitive match.
Q()
iexact
class attributes
range

40. If you pickle a QuerySet - this will force all the results to be loaded into memory prior to pickling. When you unpickle a QuerySet - it contains the results at the moment it was pickled - rather than the results that are currently in the database.
ordered
get_or_create(**kwargs)
pickling
null

41. 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.
latest(field_name=None)
in_bulk(id_list)
save()
Abstract base class

42. Returns a ValuesQuerySet -- a QuerySet that returns dictionaries when used as an iterable - rather than model-instance objects.
values(*fields)
get_absolute_url()
model
distinct()

43. These add custom "row-level" functionality to your objects. These act on a particular model instance.
Custom model methods
values(*fields)
~
all()

44. A QuerySet is iterable - and it executes its database query the first time you iterate over it.
Q()
iteration
class attributes
istartswith

45. This method is for controlling which database the QuerySet will be evaluated against if you are using more than one database. The only argument this method takes is the alias of a database - as defined in DATABASES.
values_list(*fields)
using(alias)
select_related()
count()

46. This represents a collection of objects from your database. It can have zero - one or many filters.
QuerySet
Q()
edit your settings file and change the INSTALLED_APPS setting to add the name of the module that contains your models.py.
startswith

47. If this option is True - Django will store empty values as NULL in the database. Default is False.
MultipleObjectsReturned
aggregate(args - *kwargs)
iendswith
null

48. (1) These cannot be Python reserved words - because that would result in a Python syntax error. (2) These cannot contain more than one underscore in a row - due to the way Django's query lookup syntax works.
filter
pickling
Restrictions on field names
lte

49. Defines a many-to-one relationship. ou use it just like any other Field type: by including it as a class attribute of your model.
ForeignKey
Manager methods
get(**kwargs)
latest(field_name=None)

50. A Manager method that returns a new QuerySet containing objects that match the given lookup parameters.
istartswith
through argument
filter(**kwargs)
Entry.objects.filter(id__in=[1 - 3 - 4])