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Django Queryset

Subject : it-skills

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
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. Conjuntion operator for Q objects.
&
iterator()
in_bulk(id_list)
default

2. 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

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.
gt
in_bulk(id_list)
istartswith
iexact

4. Lookup type that returns results with a case-insensitive start sequence.
iteration
exact
istartswith
model

5. Lookup type that returns results less than or equal to a given value.
lte
aggregate(args - *kwargs)
filter(**kwargs)
pickling

6. This model method saves a model instance to the database. This method has no return value.
iexact
save()
Model metadata
lt

7. Exception raised by get(**kwargs) if no items match the query.
pickling
DoesNotExist
Entry.objects.all().update(n_pingbacks=F('n_pingbacks') + 1)
through argument

8. 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()
evaluation
class attributes
pk
F()

9. Lookup type for date/datetime fields that finds a 'day of the week' match.
exclude(**kwargs)
week_day
many-to-many relationship
gte

10. 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
month
through argument
pickling
Meta class

11. The default for this is the name of the child class followed by '_set'.
reverse name
delete()
model
extra(select=None - where=None - params=None - tables=None - order_by=None - select_params=None)

12. This method immediately deletes the object and has no return value.
extra(select=None - where=None - params=None - tables=None - order_by=None - select_params=None)
choices
delete()
Custom model methods

13. This class type is useful when you just want to use the parent class to hold information that you don't want to have to type out for each child model. This class isn't going to ever be used in isolation. When it is used as a base class for other mode
Model metadata
evaluation
Abstract base class
gte

14. 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
OneToOneField
regex
contains

15. (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
filter chaining
iregex
Entry.objects.filter(pub_date__year=2007).update(headline='Everything is the same')

16. Extra text to be displayed under the field on the object's admin form to provide assistance to users. It's useful for documentation even if your object doesn't have an admin form.
|
update(**kwargs)
MultipleObjectsReturned
help_text

17. 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
Q(question__istartswith='What')
Model metadata
all()
none()

18. 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

19. 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))
aggregate(args - *kwargs)
==
only(*fields)

20. 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
intermediate models
delete()
QuerySet
many-to-one relationship

21. A convenience method for constructing an object and saving it all in one step.
Entry.objects.filter(pub_date__range=(start_date - end_date))
day
create(**kwargs)
through argument

22. 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
ManyToManyField
class type
get(**kwargs)
filter chaining

23. 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.
&
contains
help_text
choices tuple

24. Returns an integer representing the number of objects in the database matching the QuerySet. This never raises exceptions.
Entry.objects.filter(pub_date__year=2005).delete()
Many-to-many relationship to self
count()
one-to-one relationship

25. Lookup type that returns results with a case-sensitive start sequence.
class type
Many-to-many relationship to self
Entry.objects.all().update(n_pingbacks=F('n_pingbacks') + 1)
startswith

26. Each one of these is a Python class that subclasses django.db.models.Model. Each attribute of one of these represents a database field.
using(alias)
day
model
QuerySet

27. This gives your model metadata.
Meta class
class type
Restrictions on field names
many-to-one relationship

28. 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.
iendswith
slicing
==
reverse()

29. 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.
values(*fields)
exact
year
related_name

30. This represents a collection of objects from your database. It can have zero - one or many filters.
slicing
gte
__unicode__()
QuerySet

31. A Manager method that returns a new QuerySet containing objects that match the given lookup parameters.
Entry.objects.filter(id__gt=4)
dates(field - kind - order='ASC')
filter(**kwargs)
year

32. 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.
Entry.objects.filter(pub_date__range=(start_date - end_date))
update()
when you add new apps to INSTALLED_APPS
iexact

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.
choices
when you add new apps to INSTALLED_APPS
delete()
evaluation

34. This field is added automatically - but this behavior can be overridden
|
id field
class attributes
get_or_create(**kwargs)

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

36. The database that will be used if this query is executed now
Meta class
Model metadata
ManyToManyField
db

37. If True - this field is the primary key for the model.
primary_key
filter chaining
iterator()
Manager methods

38. 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
MultipleObjectsReturned
update(**kwargs)
delete()
relationship spanning

39. A Python "magic method" that returns a unicode "representation" of any object.
regex
iteration
range
__unicode__()

40. 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

41. These add custom "row-level" functionality to your objects. These act on a particular model instance.
pickling
Entry.objects.filter(id__gt=4)
Custom model methods
exists()

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.
get(**kwargs)
none()
DoesNotExist
startswith

43. Returns the object matching the given lookup parameters
slicing
ordered
save()
get(**kwargs)

44. Returns a new QuerySet containing objects that match the given lookup parameters.
ordered
lte
filter(**kwargs)
lt

45. Fields are specified by these
choices tuple
class attributes
values_list(*fields)
aggregate(args - *kwargs)

46. 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
many-to-one relationship
Q(question__startswith='Who') | ~Q(pub_date__year=2005)
iendswith
relationship spanning

47. This query deletes all Entry objects with a pub_date year of 2005.
Field lookups
Entry.objects.filter(pub_date__year=2005).delete()
Manager methods
pk

48. Lookup type that finds a case-sensitive regular expression match.
get(**kwargs)
all()
regex
range

49. This query finds all entries with an id greater than 4.
Entry.objects.filter(id__gt=4)
Custom model methods
Multi-table inheritance
select_related()

50. Lookup type for date/datetime fields that finds an exact month match. Takes an integer 1 (January) through 12
month
all()
model
in_bulk(id_list)