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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 database that will be used if this query is executed now
distinct()
==
Meta class
db

2. 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.
dates(field - kind - order='ASC')
Many-to-many relationship to self
none()
choices

3. 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
iterator()
istartswith
Field lookups
F()

4. 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.
id field
iteration
istartswith
aggregate(args - *kwargs)

5. Lookup type that returns results that fall into an inclusive date range.
relationship spanning
pickling
range
class type

6. Lookup type that returns results less than or equal to a given value.
distinct()
only(*fields)
help_text
lte

7. A convenience method for looking up an object with the given kwargs - creating one if necessary.
clear() method
none()
reverse name
get_or_create(**kwargs)

8. Lookup type for date/datetime fields that finds an exact day match.
==
Field lookups
day
exclude(**kwargs)

9. 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.
lte
contains
get_absolute_url()
dates(field - kind - order='ASC')

10. Disjunction operator for Q objects.
iendswith
choices
Entry.objects.filter(id__gt=4)
|

11. These add custom "row-level" functionality to your objects. These act on a particular model instance.
one-to-one relationship
class attributes
pk
Custom model methods

12. This query finds all entries between a start date of start_date and an end date of end_date.
search
Manager methods
startswith
Entry.objects.filter(pub_date__range=(start_date - end_date))

13. This model method is used for updating a ManyToManyField.
add()
DoesNotExist
evaluation
values_list(*fields)

14. To activate your models
edit your settings file and change the INSTALLED_APPS setting to add the name of the module that contains your models.py.
MultipleObjectsReturned
choices
Meta class

15. If this option is True - Django will store empty values as NULL in the database. Default is False.
year
unique
QuerySet
null

16. This model method saves a model instance to the database. This method has no return value.
__unicode__()
reverse()
save()
endswith

17. This represents a collection of objects from your database. It can have zero - one or many filters.
exists()
QuerySet
year
get_absolute_url()

18. Returns a new QuerySet that uses SELECT DISTINCT in its SQL query. This eliminates duplicate rows from the query results.
distinct()
filter chaining
iendswith
Entry.objects.filter(pub_date__range=(start_date - end_date))

19. 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
ForeignKey
F()
choices
Entry.objects.filter(id__gt=4)

20. 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.
Many-to-many relationship through an intermediate model
annotate(args - *kwargs)
order_by(*fields)
MultipleObjectsReturned

21. If True - this field is the primary key for the model.
Entry.objects.filter(id__gt=4)
primary_key
&
extra(select=None - where=None - params=None - tables=None - order_by=None - select_params=None)

22. 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.
null
intermediate models
ForeignKey
__unicode__()

23. A QuerySet is iterable - and it executes its database query the first time you iterate over it.
filter(**kwargs)
iteration
edit your settings file and change the INSTALLED_APPS setting to add the name of the module that contains your models.py.
latest(field_name=None)

24. 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)
update(**kwargs)
Model metadata
many-to-one relationship
evaluation

25. Lookup type that finds a case-insensitive regular expression match.
iregex
aggregate(args - *kwargs)
help_text
defer(*fields)

26. Returns an EmptyQuerySet -- a QuerySet that always evaluates to an empty list. This can be used in cases where you know that you should return an empty result set and your caller is expecting a QuerySet object (instead of returning an empty list - fo
only(*fields)
none()
year
values_list(*fields)

27. 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
null
Entry.objects.filter(pub_date__year=2005).delete()
class type
iendswith

28. This method immediately deletes the object and has no return value.
get_absolute_url()
F()
delete()
Custom model methods

29. 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

30. Conjuntion operator for Q objects.
clear() method
&
delete()
year

31. 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.
ForeignKey
count()
endswith
using(alias)

32. 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.
Model metadata
Entry.objects.filter(pub_date__year=2005).delete()
~
choices

33. A Manager method that returns a new QuerySet containing objects that match the given lookup parameters.
filter(**kwargs)
save()
OneToOneField
Field lookups

34. Returns the most recent object in the table - by date - using the field_name provided as the date field.
delete()
primary_key
month
latest(field_name=None)

35. Lookup type for date/datetime fields that finds an exact year match. Takes a four-digit year.
create(**kwargs)
filter(**kwargs)
values_list(*fields)
year

36. Exception raised by get(**kwargs) if more than one item matches the query.
filter(**kwargs)
update()
Model metadata
MultipleObjectsReturned

37. Fields are specified by these
slicing
one-to-one relationship
Restrictions on field names
class attributes

38. Lookup type that returns results with a case-insensitive start sequence.
istartswith
add()
blank
primary_key

39. 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.
order_by(*fields)
Entry.objects.filter(id__gt=4)
dates(field - kind - order='ASC')
class attributes

40. This query finds all entries with an id in the list [1 - 3 - 4]
Entry.objects.filter(id__in=[1 - 3 - 4])
reverse name
ForeignKey
class attributes

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.
in_bulk(id_list)
delete()
values_list(*fields)
in

42. 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.
update(**kwargs)
get(**kwargs)
isnull
exclude(**kwargs)

43. 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
exists()
through argument
none()
F()

44. 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.
Custom model methods
__unicode__()
endswith
default

45. Exception raised by get(**kwargs) if no items match the query.
day
Entry.objects.all().update(n_pingbacks=F('n_pingbacks') + 1)
DoesNotExist
aggregate(args - *kwargs)

46. Returns a new QuerySet containing objects that match the given lookup parameters.
filter(**kwargs)
|
Entry.objects.filter(pub_date__range=(start_date - end_date))
Manager methods

47. This is a criterion that narrow down a QuerySet based on given parameters.
filter
help_text
week_day
get_or_create(**kwargs)

48. 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.
endswith
Multi-table inheritance
day
intermediate models

49. Used to get a QuerySet for a model. This is called 'objects' by default.
none()
order_by(*fields)
class attributes
Manager

50. 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.
filter(**kwargs)
edit your settings file and change the INSTALLED_APPS setting to add the name of the module that contains your models.py.
reverse()
only(*fields)