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Django Queryset

Subject : it-skills

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Answer 50 questions in 15 minutes.
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Match each statement with the correct term.
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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. 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.
only(*fields)
edit your settings file and change the INSTALLED_APPS setting to add the name of the module that contains your models.py.
Entry.objects.filter(pub_date__year=2005).delete()
Many-to-many relationship to self

2. 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.
iteration
exists()
Q(question__startswith='Who') | ~Q(pub_date__year=2005)
order_by(*fields)

3. 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.
all()
dates(field - kind - order='ASC')
model
search

4. The default for this is the name of the child class followed by '_set'.
relationship spanning
order_by(*fields)
reverse name
search

5. Returns the most recent object in the table - by date - using the field_name provided as the date field.
exclude(**kwargs)
Entry.objects.filter(pub_date__year=2007).update(headline='Everything is the same')
Entry.objects.filter(id__gt=4)
latest(field_name=None)

6. Keyword shortcut for looking up an object by primary key.
pk
select_related()
isnull
class type

7. These add custom "row-level" functionality to your objects. These act on a particular model instance.
year
count()
order_by(*fields)
Custom model methods

8. (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.
values(*fields)
filter
Restrictions on field names
month

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

10. Fields are specified by these
class attributes
Q(question__istartswith='What')
choices
year

11. This method immediately deletes the object and has no return value.
delete()
Custom model methods
Q(question__istartswith='What')
iexact

12. This query deletes all Entry objects with a pub_date year of 2005.
ordered
none()
Entry.objects.filter(pub_date__year=2005).delete()
pickling

13. Lookup type that finds a case-insensitive regular expression match.
endswith
iregex
Abstract base class
choices

14. 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
related_name
choices
slicing

15. 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.
class type
&
choices tuple
gte

16. 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.
week_day
Entry.objects.filter(id__in=[1 - 3 - 4])
Abstract base class
Q()

17. 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.
pickling
iexact
one-to-one relationship
Manager

18. To activate your models
DoesNotExist
&
Proxy model
edit your settings file and change the INSTALLED_APPS setting to add the name of the module that contains your models.py.

19. Returns a ValuesQuerySet -- a QuerySet that returns dictionaries when used as an iterable - rather than model-instance objects.
values(*fields)
order_by(*fields)
primary_key
Q()

20. If you are using this attribute on a ForeignKey or ManyToManyField - you must always specify a unique reverse name for the field.
contains
related_name
filter(**kwargs)
blank

21. 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)
help_text
~
search

22. 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

23. This model method is used for updating a ManyToManyField.
count()
filter(**kwargs)
reverse name
add()

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
get_absolute_url()
in_bulk(id_list)
only(*fields)
Entry.objects.filter(id__in=[1 - 3 - 4])

25. 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.
values_list(*fields)
annotate(args - *kwargs)
latest(field_name=None)
Manager methods

26. Lookup type that finds a case-sensitive regular expression match.
regex
choices
distinct()
all()

27. 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

28. 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
get(**kwargs)
default
endswith

29. 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.
Entry.objects.filter(id__in=[1 - 3 - 4])
ManyToManyField
extra(select=None - where=None - params=None - tables=None - order_by=None - select_params=None)
Manager methods

30. 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.
get_absolute_url()
gte
OneToOneField
Proxy model

31. 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.
update()
dates(field - kind - order='ASC')
&
endswith

32. 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

33. A Python "magic method" that returns a unicode "representation" of any object.
values(*fields)
get(**kwargs)
Entry.objects.filter(pub_date__year=2007).update(headline='Everything is the same')
__unicode__()

34. These are "anything that's not a field" - such as ordering options (ordering) - database table name (db_table) - or human-readable singular and plural names (verbose_name and verbose_name_plural)
gt
Entry.objects.filter(id__in=[1 - 3 - 4])
Multi-table inheritance
Model metadata

35. True if the QuerySet has an order_by() clause or a default ordering on the model. False otherwise.
Entry.objects.filter(id__gt=4)
choices tuple
iexact
ordered

36. This is a criterion that narrow down a QuerySet based on given parameters.
Entry.objects.filter(pub_date__year=2005).delete()
values_list(*fields)
filter
|

37. These are specified as keyword arguments to the QuerySet methods filter() - exclude() and get(). These take the form field__lookuptype=value .
using(alias)
Field lookups
filter(**kwargs)
exists()

38. Lookup type that returns results less than or equal to a given value.
Q()
lte
get_or_create(**kwargs)
primary_key

39. Lookup type that yields a case-insensitive match.
update()
dates(field - kind - order='ASC')
model
iexact

40. A QuerySet is iterable - and it executes its database query the first time you iterate over it.
annotate(args - *kwargs)
get(**kwargs)
iteration
choices

41. Each one of these is a Python class that subclasses django.db.models.Model. Each attribute of one of these represents a database field.
select_related()
id field
F()
model

42. Lookup type that returns results greater than a given value.
Multi-table inheritance
F()
gte
gt

43. This query finds all entries between a start date of start_date and an end date of end_date.
==
reverse()
Entry.objects.filter(pub_date__range=(start_date - end_date))
in_bulk(id_list)

44. These methods are intended to do "table-wide" things.
Manager methods
istartswith
Restrictions on field names
Proxy model

45. 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
F()
blank
intermediate models
Q(question__istartswith='What')

46. Lookup type that returns results with a case-sensitive end sequence.
intermediate models
endswith
only(*fields)
in

47. Lookup type that returns results with a case-sensitive start sequence.
count()
startswith
Abstract base class
F()

48. If True - this field is the primary key for the model.
primary_key
|
==
endswith

49. Lookup type that returns results with a case-insensitive end sequence.
help_text
iendswith
model
defer(*fields)

50. 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
extra(select=None - where=None - params=None - tables=None - order_by=None - select_params=None)
startswith
update(**kwargs)
Proxy model