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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. A Python "magic method" that returns a unicode "representation" of any object.
year
range
__unicode__()
through argument

2. Can be used to remove all many-to-many relationships for an instance
clear() method
ordered
delete()
week_day

3. 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
exists()
Proxy model
Many-to-many relationship to self
none()

4. If you are using this attribute on a ForeignKey or ManyToManyField - you must always specify a unique reverse name for the field.
related_name
Q()
relationship spanning
gte

5. 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.
only(*fields)
values_list(*fields)
many-to-one relationship
select_related()

6. The default for this is the name of the child class followed by '_set'.
dates(field - kind - order='ASC')
only(*fields)
reverse name
update(**kwargs)

7. A convenience method for constructing an object and saving it all in one step.
isnull
filter
Entry.objects.filter(pub_date__year=2007).update(headline='Everything is the same')
create(**kwargs)

8. Each one of these is a Python class that subclasses django.db.models.Model. Each attribute of one of these represents a database field.
model
exact
class type
values_list(*fields)

9. 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
slicing
OneToOneField
reverse()
class type

10. 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.
isnull
Custom model methods
endswith
update()

11. 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)
Model metadata
Q(question__startswith='Who') | ~Q(pub_date__year=2005)
pickling
F()

12. Lookup type that returns results with a case-sensitive start sequence.
startswith
help_text
Entry.objects.filter(pub_date__range=(start_date - end_date))
only(*fields)

13. 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
Manager
lt
filter chaining
through argument

14. Lookup type that returns results with a case-sensitive end sequence.
endswith
Many-to-many relationship through an intermediate model
add()
primary_key

15. When to run syncdb
isnull
update()
when you add new apps to INSTALLED_APPS
F()

16. 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.
when you add new apps to INSTALLED_APPS
relationship spanning
reverse()
OneToOneField

17. This method immediately deletes the object and has no return value.
Restrictions on field names
lt
delete()
range

18. 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
DoesNotExist
exact
annotate(args - *kwargs)
when you add new apps to INSTALLED_APPS

19. 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.
pk
aggregate(args - *kwargs)
iterator()
many-to-one relationship

20. This model method saves a model instance to the database. This method has no return value.
save()
Model metadata
month
none()

21. Returns the object matching the given lookup parameters
only(*fields)
get_absolute_url()
endswith
get(**kwargs)

22. Manager method used to retrieve every object in a model.
all()
ForeignKey
gte
QuerySet

23. This query finds all entries with an id greater than 4.
ordered
Q(question__istartswith='What')
Entry.objects.filter(id__gt=4)
clear() method

24. These methods are intended to do "table-wide" things.
Manager methods
unique
Many-to-many relationship through an intermediate model
edit your settings file and change the INSTALLED_APPS setting to add the name of the module that contains your models.py.

25. 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.
in_bulk(id_list)
&
Restrictions on field names
ForeignKey

26. 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))
&
endswith
all()

27. The database that will be used if this query is executed now
startswith
gte
db
|

28. Lookup type that returns results with a case-insensitive start sequence.
istartswith
class attributes
model
Q(question__startswith='Who') | ~Q(pub_date__year=2005)

29. This field is added automatically - but this behavior can be overridden
id field
Many-to-many relationship through an intermediate model
select_related()
isnull

30. Defined by a OneToOneField. You use it just like any other Field type: by including it as a class attribute of your model.
startswith
relationship spanning
Q(question__startswith='Who') | ~Q(pub_date__year=2005)
one-to-one relationship

31. True if the QuerySet has an order_by() clause or a default ordering on the model. False otherwise.
when you add new apps to INSTALLED_APPS
evaluation
ordered
MultipleObjectsReturned

32. 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
aggregate(args - *kwargs)
filter
defer(*fields)
db

33. Lookup type that returns results less than or equal to a given value.
Many-to-many relationship to self
lte
exists()
get_or_create(**kwargs)

34. Takes the ouput of one filter and uses it as input for another filter. This works because a refinement of a QuerySet is itself a QuerySet.
class attributes
OneToOneField
get_absolute_url()
filter chaining

35. A manager method that returns a new QuerySet containing objects that do not match the given lookup parameters.
Many-to-many relationship through an intermediate model
lte
get(**kwargs)
exclude(**kwargs)

36. Returns a ValuesQuerySet -- a QuerySet that returns dictionaries when used as an iterable - rather than model-instance objects.
values(*fields)
day
default
Entry.objects.filter(pub_date__year=2005).delete()

37. 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.
none()
using(alias)
Model metadata
F()

38. 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

39. 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.
values(*fields)
values_list(*fields)
extra(select=None - where=None - params=None - tables=None - order_by=None - select_params=None)
OneToOneField

40. These are specified as keyword arguments to the QuerySet methods filter() - exclude() and get(). These take the form field__lookuptype=value .
exact
save()
isnull
Field lookups

41. 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.
gte
contains
unique
Multi-table inheritance

42. Lookup type for date/datetime fields that finds a 'day of the week' match.
Custom model methods
week_day
ForeignKey
Proxy model

43. If True - this field is the primary key for the model.
day
primary_key
Q()
none()

44. Returns a new QuerySet containing objects that match the given lookup parameters.
help_text
filter(**kwargs)
update()
choices tuple

45. A Manager method that returns a new QuerySet containing objects that match the given lookup parameters.
through argument
filter(**kwargs)
isnull
==

46. If this option is True - Django will store empty values as NULL in the database. Default is False.
create(**kwargs)
null
many-to-many relationship
iterator()

47. 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
defer(*fields)

48. Defines a many-to-many relationship. You use it just like any other Field type: by including it as a class attribute of your model.
null
ManyToManyField
exclude(**kwargs)
class type

49. 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
month
in_bulk(id_list)
Entry.objects.all().update(n_pingbacks=F('n_pingbacks') + 1)

50. 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