Test your basic knowledge |

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. 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


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






3. Returns True if the QuerySet contains any results - and False if not. This tries to perform the query in the simplest and fastest way possible - but it does execute nearly the same query. This means that calling this method on a queryset is faster th






4. 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.






5. 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






6. 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






7. Can be used to remove all many-to-many relationships for an instance






8. Lookup type that returns results greater than a given value.






9. 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.






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.






11. a QuerySet can be sliced - using Python's array-slicing syntax.






12. A manager method that returns a new QuerySet containing objects that do not match the given lookup parameters.






13. This gives your model metadata.






14. Lookup type that returns results less than or equal to a given value.






15. 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.






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






17. 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






18. 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.






19. This field is added automatically - but this behavior can be overridden






20. Lookup type that returns results greater than or equal to a given value.






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






22. 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.






23. 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






24. Returns an integer representing the number of objects in the database matching the QuerySet. This never raises exceptions.






25. These add custom "row-level" functionality to your objects. These act on a particular model instance.






26. Negation operator for Q objects.






27. Lookup type that finds a case-sensitive regular expression match.






28. Returns a DateQuerySet -- a QuerySet that evaluates to a list of datetime.datetime objects representing all available dates of a particular kind within the contents of the QuerySet.

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183


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






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.






31. 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.






32. 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


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






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






35. 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.






36. Returns the object matching the given lookup parameters






37. 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






38. Lookup type that returns results less than a given value.






39. 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.






40. When to run syncdb






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






42. 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.






43. Fields are specified by these






44. 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.






45. This query deletes all Entry objects with a pub_date year of 2005.






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






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






48. 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.






49. Lookup type that returns results with a case-insensitive start sequence.






50. 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.