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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. The value given in the absence of a specified value for the field. This can be a value or a callable object. If callable it will be called every time a new object is created.
delete()
choices
default
many-to-one relationship

2. Lookup type for date/datetime fields that finds an exact day match.
|
Manager
day
F()

3. 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.
delete()
in_bulk(id_list)
using(alias)
add()

4. (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.
Restrictions on field names
choices tuple
iregex
defer(*fields)

5. A Q object that asks for entries with a question value that start with 'Who' or do not have a publication date of 2005.

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

6. Keyword shortcut for looking up an object by primary key.
many-to-one relationship
pk
choices tuple
iregex

7. Returns an integer representing the number of objects in the database matching the QuerySet. This never raises exceptions.
Custom model methods
count()
all()
Meta class

8. 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.
id field
Entry.objects.filter(pub_date__range=(start_date - end_date))
filter chaining
get(**kwargs)

9. This model method saves a model instance to the database. This method has no return value.
lte
Manager methods
null
save()

10. 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.
istartswith
iregex
order_by(*fields)
Many-to-many relationship to self

11. Lookup type that tests for inclusion in a case-sensitive fashion.
many-to-many relationship
Multi-table inheritance
contains
model

12. Returns a new QuerySet that uses SELECT DISTINCT in its SQL query. This eliminates duplicate rows from the query results.
iterator()
distinct()
dates(field - kind - order='ASC')
day

13. 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.
&
year
filter chaining
clear() method

14. Lookup type for date/datetime fields that finds a 'day of the week' match.
update()
week_day
Many-to-many relationship to self
__unicode__()

15. Fields are specified by these
class attributes
order_by(*fields)
when you add new apps to INSTALLED_APPS
get(**kwargs)

16. This model method is used for updating a ManyToManyField.
class type
ordered
annotate(args - *kwargs)
add()

17. 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.
many-to-one relationship
gte
Field lookups
relationship spanning

18. Returns a new QuerySet containing objects that match the given lookup parameters.
DoesNotExist
reverse()
pickling
filter(**kwargs)

19. 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
__unicode__()
id field
update(**kwargs)
week_day

20. 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.
Manager
endswith
relationship spanning
extra(select=None - where=None - params=None - tables=None - order_by=None - select_params=None)

21. 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
Proxy model
gte
Q(question__istartswith='What')
range

22. These add custom "row-level" functionality to your objects. These act on a particular model instance.
Custom model methods
in
through argument
|

23. Disjunction operator for Q objects.
|
ManyToManyField
__unicode__()
iteration

24. These methods are intended to do "table-wide" things.
Model metadata
Manager methods
istartswith
regex

25. This query finds all entries with an id greater than 4.
Entry.objects.filter(id__gt=4)
update()
endswith
OneToOneField

26. When to run syncdb
|
many-to-one relationship
when you add new apps to INSTALLED_APPS
null

27. 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.
MultipleObjectsReturned
OneToOneField
gt
get(**kwargs)

28. Defines a many-to-many relationship. You use it just like any other Field type: by including it as a class attribute of your model.
save()
class attributes
pk
ManyToManyField

29. 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.
DoesNotExist
delete()
Many-to-many relationship to self
get_absolute_url()

30. 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.
using(alias)
default
evaluation
Q()

31. Returns a DateQuerySet -- a QuerySet that evaluates to a list of datetime.datetime objects representing all available dates of a particular kind within the contents of the QuerySet.

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

32. Used to get a QuerySet for a model. This is called 'objects' by default.
Q()
regex
Meta class
Manager

33. An iterable (e.g. - a list or tuple) of 2-tuples to use as options for this field. If this is given - Django's admin will use a select box instead of the standard text field and will limit options to those given.
related_name
choices
~
__unicode__()

34. Lookup type that returns results greater than or equal to a given value.
gte
F()
clear() method
aggregate(args - *kwargs)

35. Returns the object matching the given lookup parameters
MultipleObjectsReturned
get(**kwargs)
month
F()

36. 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()
values(*fields)
Multi-table inheritance
save()

37. Lookup type that returns results that fall into an inclusive date range.
Field lookups
range
~
exclude(**kwargs)

38. To activate your models
==
Q()
values_list(*fields)
edit your settings file and change the INSTALLED_APPS setting to add the name of the module that contains your models.py.

39. If this option is True - the field is allowed to be blank. Default is False.
aggregate(args - *kwargs)
Entry.objects.filter(id__gt=4)
filter chaining
blank

40. Lookup type that finds a case-sensitive regular expression match.
many-to-many relationship
latest(field_name=None)
__unicode__()
regex

41. Defined by a OneToOneField. You use it just like any other Field type: by including it as a class attribute of your model.
one-to-one relationship
OneToOneField
Many-to-many relationship through an intermediate model
clear() method

42. Lookup type for date/datetime fields that finds an exact month match. Takes an integer 1 (January) through 12
Entry.objects.filter(pub_date__range=(start_date - end_date))
month
add()
choices tuple

43. If True - the table does not permit duplicate values for this field.
unique
Entry.objects.filter(id__gt=4)
Q()
when you add new apps to INSTALLED_APPS

44. This query finds all entries between a start date of start_date and an end date of end_date.
Entry.objects.filter(pub_date__range=(start_date - end_date))
edit your settings file and change the INSTALLED_APPS setting to add the name of the module that contains your models.py.
blank
id field

45. This object encapsulates a collection of keyword arguments - with the keys being field lookup types. These objects can be combined using the & and | operators - as well as negated with the ~ operator.
|
Q()
latest(field_name=None)
primary_key

46. Lookup type that returns results in a given list.
update()
all()
in
one-to-one relationship

47. 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.
choices tuple
Meta class
Entry.objects.filter(id__in=[1 - 3 - 4])
defer(*fields)

48. Lookup type that returns results less than or equal to a given value.
~
lte
class attributes
exists()

49. This tells Django how to calculate the URL for an object. Django uses this in its admin interface - and any time it needs to figure out a URL for an object.
Q(question__startswith='Who') | ~Q(pub_date__year=2005)
distinct()
get_absolute_url()
blank

50. This query finds all entries with an id in the list [1 - 3 - 4]
Entry.objects.filter(id__in=[1 - 3 - 4])
using(alias)
filter
intermediate models