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. 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






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






3. 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.






4. 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






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






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






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






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






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






10. Lookup type for date/datetime fields that finds a 'day of the week' match.






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






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






13. 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






14. Negation operator for Q objects.






15. 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.






16. 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.






17. True if the QuerySet has an order_by() clause or a default ordering on the model. False otherwise.






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






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






20. 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.






21. Returns a new QuerySet that uses SELECT DISTINCT in its SQL query. This eliminates duplicate rows from the query results.






22. Exception raised by get(**kwargs) if no items match the query.






23. A Q object that encapsulates queries for entries with a question value that starts with 'What' in a case-insensitive fashion.


24. Lookup type that finds a case-insensitive regular expression match.






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






26. 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






27. 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()






28. 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






29. 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.






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






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






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






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






34. Disjunction operator for Q objects.






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






36. 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






37. 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.






38. 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.






39. If True - the table does not permit duplicate values for this field.






40. This query uses an F object to increment the pingback count for every entry in the blog.


41. If True - this field is the primary key for the model.






42. 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






43. 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.






44. The default for this is the name of the child class followed by '_set'.






45. 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.






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






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.






48. This query finds all entries with an id in the list [1 - 3 - 4]






49. 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






50. 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