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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. Defined by a ManyToManyField. You use it just like any other Field type: by including it as a class attribute of your model.






2. 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.






3. Lookup type that takes either True or False and corresponds to SQL queries of IS NULL and IS NOT NULL - respectively.






4. This query finds all entries with an id greater than 4.






5. A convenience method for looking up an object with the given kwargs - creating one if necessary.






6. When to run syncdb






7. 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






8. If this option is True - the field is allowed to be blank. Default is False.






9. 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






10. 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.






11. These methods are intended to do "table-wide" things.






12. 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






13. 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






14. A convenience method for constructing an object and saving it all in one step.






15. 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.






16. This represents a collection of objects from your database. It can have zero - one or many filters.






17. 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.






18. Lookup type that yields a case-insensitive match.






19. Keyword shortcut for looking up an object by primary key.






20. 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.






21. (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.






22. 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.






23. Returns the most recent object in the table - by date - using the field_name provided as the date field.






24. This query finds all entries between a start date of start_date and an end date of end_date.






25. 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.






26. A QuerySet is iterable - and it executes its database query the first time you iterate over it.






27. To activate your models






28. 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.






29. 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.






30. A Manager method that returns a new QuerySet containing objects that match the given lookup parameters.






31. 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.






32. Operator for comparing two model instances for equality. Behind the scenes - it compares the primary key values of two models.






33. 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.






34. 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.






35. 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.






36. 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






37. Fields are specified by these






38. 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


39. 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


40. Lookup type that returns results in a given list.






41. This model method saves a model instance to the database. This method has no return value.






42. Negation operator for Q objects.






43. If this option is True - Django will store empty values as NULL in the database. Default is False.






44. 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.






45. Exception raised by get(**kwargs) if more than one item matches the query.






46. 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.






47. 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






48. This gives your model metadata.






49. 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






50. 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.