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. When to run syncdb






2. This gives your model metadata.






3. 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






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






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






6. 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.






7. This is a criterion that narrow down a QuerySet based on given parameters.






8. 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.






9. 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.






10. 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.






11. Returns a QuerySet that will automatically "follow" foreign-key relationships - selecting that additional related-object data when it executes its query. This is a performance booster which results in (sometimes much) larger queries but means later u






12. Lookup type that returns results with a case-sensitive end sequence.






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






14. Manager method used to retrieve every object in a model.






15. 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






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






17. To activate your models






18. This object allows you to compare the value of a model field with another field on the same model. Django supports the use of addition - subtraction - multiplication - division and modulo arithmetic with these objects - both with constants and with o






19. Each one of these is a Python class that subclasses django.db.models.Model. Each attribute of one of these represents a database field.






20. 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


21. Negation operator for Q objects.






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






23. Lookup type that returns results that fall into an inclusive date range.






24. 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.






25. Lookup type that returns results with a case-insensitive end sequence.






26. 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.






27. These are specified as keyword arguments to the QuerySet methods filter() - exclude() and get(). These take the form field__lookuptype=value .






28. 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.






29. 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






30. 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.






31. 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






32. Returns a copy of the current QuerySet (or QuerySet subclass you pass in). This can be useful in some situations where you might want to pass in either a model manager or a QuerySet and do further filtering on the result. You can safely call all() on






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






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






35. Returns a new QuerySet containing objects that match the given lookup parameters.






36. This model method is used for updating a ManyToManyField.






37. This method immediately deletes the object and has no return value.






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






39. 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.






40. Lookup type that tests for inclusion in a case-sensitive fashion.






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






42. 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


43. 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.






44. 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






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






46. 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()






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






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






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






50. If you are using this attribute on a ForeignKey or ManyToManyField - you must always specify a unique reverse name for the field.