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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 returns results greater than a given value.
gt
class type
dates(field - kind - order='ASC')
exclude(**kwargs)

2. 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
Entry.objects.filter(id__gt=4)
through argument
month
isnull

3. The default for this is the name of the child class followed by '_set'.
Entry.objects.filter(id__gt=4)
Manager methods
DoesNotExist
reverse name

4. If True - this field is the primary key for the model.
week_day
blank
Manager
primary_key

5. Lookup type that takes either True or False and corresponds to SQL queries of IS NULL and IS NOT NULL - respectively.
isnull
values_list(*fields)
relationship spanning
save()

6. 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
dates(field - kind - order='ASC')
filter(**kwargs)
F()
choices

7. 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.
create(**kwargs)
choices tuple
ForeignKey
primary_key

8. Lookup type that returns results that fall into an inclusive date range.
Manager
filter(**kwargs)
get_absolute_url()
range

9. Manager method used to retrieve every object in a model.
reverse()
defer(*fields)
clear() method
all()

10. A manager method that returns a new QuerySet containing objects that do not match the given lookup parameters.
month
exclude(**kwargs)
lt
F()

11. 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)
many-to-one relationship
contains
in

12. Lookup type that returns results greater than or equal to a given value.
aggregate(args - *kwargs)
db
gte
filter chaining

13. Conjuntion operator for Q objects.
&
reverse()
QuerySet
filter(**kwargs)

14. These methods are intended to do "table-wide" things.
get_or_create(**kwargs)
pk
select_related()
Manager methods

15. This field is added automatically - but this behavior can be overridden
annotate(args - *kwargs)
contains
iterator()
id field

16. 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
lte
help_text
intermediate models
class attributes

17. If this option is True - Django will store empty values as NULL in the database. Default is False.
null
F()
relationship spanning
Restrictions on field names

18. what the field _______ determines: (1) The database column type (e.g. INTEGER - VARCHAR); (2) The widget to use in Django's admin interface - if you care to use it (e.g. <input type="text"> - <select>); (3) The minimal validation requirements - used
class type
Meta class
istartswith
Model metadata

19. This style of inheritanc is useful when you're subclassing an existing model (perhaps something from another application entirely) and want each model to have its own database table. Here - each model in the hierarchy is a model all by itself.
gt
get(**kwargs)
week_day
Multi-table inheritance

20. In some complex data-modeling situations - your models might contain a lot of fields - some of which could contain a lot of data (for example - text fields) - or require expensive processing to convert them to Python objects. If you are using the res
defer(*fields)
delete()
iteration
count()

21. Lookup type that returns results less than a given value.
lt
filter(**kwargs)
Meta class
blank

22. Evaluates the QuerySet (by performing the query) and returns an iterator over the results. A QuerySet typically caches its results internally so that repeated evaluations do not result in additional queries; this method will instead read results dire
day
clear() method
iterator()
count()

23. Here - you can't use add - create - or assignment (i.e. - beatles.members = [...]) to create relationships. You need to specify all the detail for the relationship required by the intermediate model.
in_bulk(id_list)
Entry.objects.filter(pub_date__range=(start_date - end_date))
Many-to-many relationship through an intermediate model
Entry.objects.filter(pub_date__year=2007).update(headline='Everything is the same')

24. True if the QuerySet has an order_by() clause or a default ordering on the model. False otherwise.
DoesNotExist
Q()
update(**kwargs)
ordered

25. Exception raised by get(**kwargs) if more than one item matches the query.
help_text
exclude(**kwargs)
all()
MultipleObjectsReturned

26. If this option is True - the field is allowed to be blank. Default is False.
blank
through argument
all()
latest(field_name=None)

27. 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
get_absolute_url()
choices tuple
relationship spanning
annotate(args - *kwargs)

28. This query deletes all Entry objects with a pub_date year of 2005.
Entry.objects.filter(pub_date__year=2005).delete()
Proxy model
clear() method
exact

29. Fields are specified by these
Q(question__istartswith='What')
class attributes
F()
evaluation

30. 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.
Entry.objects.filter(pub_date__range=(start_date - end_date))
delete()
choices
exact

31. This query uses an F object to increment the pingback count for every entry in the blog.

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

32. 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.
filter(**kwargs)
related_name
endswith
Q()

33. 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.
extra(select=None - where=None - params=None - tables=None - order_by=None - select_params=None)
choices
all()
Custom model methods

34. These are specified as keyword arguments to the QuerySet methods filter() - exclude() and get(). These take the form field__lookuptype=value .
id field
related_name
Field lookups
filter(**kwargs)

35. This query finds all entries with an id in the list [1 - 3 - 4]
&
Entry.objects.filter(id__in=[1 - 3 - 4])
class type
range

36. The database that will be used if this query is executed now
db
year
Meta class
update(**kwargs)

37. A convenience method for looking up an object with the given kwargs - creating one if necessary.
Q(question__istartswith='What')
iexact
class type
get_or_create(**kwargs)

38. A Manager method that returns a new QuerySet containing objects that match the given lookup parameters.
year
many-to-one relationship
gt
filter(**kwargs)

39. (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.
reverse name
Restrictions on field names
extra(select=None - where=None - params=None - tables=None - order_by=None - select_params=None)
Manager methods

40. Operator for comparing two model instances for equality. Behind the scenes - it compares the primary key values of two models.
Meta class
F()
==
reverse name

41. Can be used to remove all many-to-many relationships for an instance
clear() method
reverse()
get_or_create(**kwargs)
Manager

42. Lookup type that returns results with a case-sensitive end sequence.
endswith
Entry.objects.filter(pub_date__range=(start_date - end_date))
delete()
defer(*fields)

43. Lookup type that finds a case-insensitive regular expression match.
clear() method
unique
exact
iregex

44. 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

45. 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.
Manager
search
&
Field lookups

46. 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

47. 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()
Multi-table inheritance
only(*fields)
pk

48. This model method saves a model instance to the database. This method has no return value.
save()
select_related()
startswith
through argument

49. 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.
default
values_list(*fields)
Q()
filter(**kwargs)

50. Returns a new QuerySet that uses SELECT DISTINCT in its SQL query. This eliminates duplicate rows from the query results.
MultipleObjectsReturned
Entry.objects.filter(id__in=[1 - 3 - 4])
many-to-many relationship
distinct()