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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. 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.






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






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






4. 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






5. 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






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






7. 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.






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






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






10. 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


11. 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.






12. 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.






13. 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)






14. 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






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. 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.






17. 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.






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






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






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






21. The first element in this iterable is the value that will be stored in the database - the second element will be displayed by the admin interface - or in a ModelChoiceField.






22. Conjuntion operator for Q objects.






23. 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.






24. 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






25. 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.






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






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






28. 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






29. Disjunction operator for Q objects.






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






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






32. 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






33. Lookup type for date/datetime fields that finds an exact year match. Takes a four-digit year.






34. 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()






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






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






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






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






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






40. Returns the object matching the given lookup parameters






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






42. 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.






43. 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.






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






45. 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






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






47. 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






48. 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.






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






50. 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.