SUBJECTS
|
BROWSE
|
CAREER CENTER
|
POPULAR
|
JOIN
|
LOGIN
Business Skills
|
Soft Skills
|
Basic Literacy
|
Certifications
About
|
Help
|
Privacy
|
Terms
|
Email
Search
Test your basic knowledge |
Django Queryset
Start Test
Study First
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. A convenience method for looking up an object with the given kwargs - creating one if necessary.
save()
range
Many-to-many relationship through an intermediate model
get_or_create(**kwargs)
2. 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
reverse()
get(**kwargs)
all()
3. This model method saves a model instance to the database. This method has no return value.
distinct()
none()
save()
get_absolute_url()
4. Operator for comparing two model instances for equality. Behind the scenes - it compares the primary key values of two models.
==
using(alias)
unique
delete()
5. 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
relationship spanning
none()
intermediate models
all()
6. When to run syncdb
select_related()
Many-to-many relationship to self
when you add new apps to INSTALLED_APPS
delete()
7. This model method is used for updating a ManyToManyField.
lt
Model metadata
add()
help_text
8. Returns a new QuerySet containing objects that match the given lookup parameters.
Custom model methods
select_related()
Manager
filter(**kwargs)
9. If True - this field is the primary key for the model.
&
aggregate(args - *kwargs)
primary_key
filter(**kwargs)
10. 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.
dates(field - kind - order='ASC')
Custom model methods
OneToOneField
delete()
11. 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
get_absolute_url()
aggregate(args - *kwargs)
intermediate models
12. 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
13. Lookup type that returns results greater than or equal to a given value.
Multi-table inheritance
filter
gte
Q()
14. 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.
choices
Multi-table inheritance
Entry.objects.filter(pub_date__year=2007).update(headline='Everything is the same')
Q(question__startswith='Who') | ~Q(pub_date__year=2005)
15. 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.
unique
ForeignKey
ordered
search
16. 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.
year
many-to-one relationship
DoesNotExist
iendswith
17. Manager method used to retrieve every object in a model.
dates(field - kind - order='ASC')
id field
gte
all()
18. 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.
DoesNotExist
order_by(*fields)
get(**kwargs)
in_bulk(id_list)
19. Disjunction operator for Q objects.
model
Entry.objects.filter(pub_date__range=(start_date - end_date))
|
in_bulk(id_list)
20. Lookup type for date/datetime fields that finds an exact day match.
slicing
lt
day
annotate(args - *kwargs)
21. This method immediately deletes the object and has no return value.
delete()
Many-to-many relationship to self
many-to-one relationship
choices tuple
22. This represents a collection of objects from your database. It can have zero - one or many filters.
QuerySet
==
blank
Custom model methods
23. True if the QuerySet has an order_by() clause or a default ordering on the model. False otherwise.
values(*fields)
ordered
Entry.objects.filter(id__in=[1 - 3 - 4])
Q(question__startswith='Who') | ~Q(pub_date__year=2005)
24. These are specified as keyword arguments to the QuerySet methods filter() - exclude() and get(). These take the form field__lookuptype=value .
~
related_name
Field lookups
latest(field_name=None)
25. A Manager method that returns a new QuerySet containing objects that match the given lookup parameters.
filter(**kwargs)
Q(question__startswith='Who') | ~Q(pub_date__year=2005)
ForeignKey
filter
26. If you are using this attribute on a ForeignKey or ManyToManyField - you must always specify a unique reverse name for the field.
Entry.objects.filter(pub_date__year=2005).delete()
week_day
delete()
related_name
27. Defined by a ManyToManyField. You use it just like any other Field type: by including it as a class attribute of your model.
__unicode__()
~
many-to-many relationship
values(*fields)
28. Lookup type that finds a case-insensitive regular expression match.
iregex
day
Field lookups
count()
29. 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.
gt
get_or_create(**kwargs)
delete()
values(*fields)
30. 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.
~
day
pickling
DoesNotExist
31. Returns the object matching the given lookup parameters
get(**kwargs)
Entry.objects.filter(id__in=[1 - 3 - 4])
Multi-table inheritance
iregex
32. These methods are intended to do "table-wide" things.
Manager methods
month
filter
distinct()
33. 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
values_list(*fields)
Q()
class type
34. a QuerySet can be sliced - using Python's array-slicing syntax.
slicing
id field
distinct()
update(**kwargs)
35. 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
latest(field_name=None)
in_bulk(id_list)
none()
through argument
36. 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.
extra(select=None - where=None - params=None - tables=None - order_by=None - select_params=None)
Q(question__startswith='Who') | ~Q(pub_date__year=2005)
update()
Many-to-many relationship to self
37. 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()
==
get_absolute_url()
class type
38. 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
distinct()
model
none()
null
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.
exists()
ordered
dates(field - kind - order='ASC')
Restrictions on field names
40. The default for this is the name of the child class followed by '_set'.
reverse name
when you add new apps to INSTALLED_APPS
Manager
many-to-one relationship
41. A convenience method for constructing an object and saving it all in one step.
lt
Restrictions on field names
filter(**kwargs)
create(**kwargs)
42. 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
43. Lookup type for date/datetime fields that finds an exact month match. Takes an integer 1 (January) through 12
all()
month
values(*fields)
primary_key
44. Lookup type that returns results that fall into an inclusive date range.
aggregate(args - *kwargs)
none()
range
related_name
45. Can be used to remove all many-to-many relationships for an instance
get(**kwargs)
all()
clear() method
primary_key
46. 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.
search
select_related()
lte
reverse()
47. 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.
using(alias)
exists()
filter chaining
extra(select=None - where=None - params=None - tables=None - order_by=None - select_params=None)
48. This query finds all entries between a start date of start_date and an end date of end_date.
OneToOneField
class attributes
MultipleObjectsReturned
Entry.objects.filter(pub_date__range=(start_date - end_date))
49. 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
search
contains
class type
Entry.objects.filter(id__gt=4)
50. Adds to each object in the QuerySet with the provided list of aggregate values (averages - sums - etc) that have been computed over the objects that are related to the objects in the QuerySet. Each argument to this is content that will be added to ea
annotate(args - *kwargs)
Many-to-many relationship to self
latest(field_name=None)
day