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






2. 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.






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

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






5. 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






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






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






8. Conjuntion operator for Q objects.






9. Defines a many-to-many relationship. You use it just like any other Field type: by including it as a class attribute of your model.






10. 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






11. A Q object that asks for entries with a question value that start with 'Who' or do not have a publication date of 2005.

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12. Fields are specified by these






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






14. 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






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






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






17. Returns the object matching the given lookup parameters






18. 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.






19. 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






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






21. 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.






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






23. Returns a ValuesQuerySet -- a QuerySet that returns dictionaries when used as an iterable - rather than model-instance objects.






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






25. Specifies the model that will be used to govern the many-to-many relationship. You can then put extra fields on the intermediate model. The intermediate model is associated with the ManyToManyField using this to point to the model that will act as an






26. Negation operator for Q objects.






27. 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.






28. 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.






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






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






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






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






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






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






35. To activate your models






36. 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.






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






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






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






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






41. 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.






42. 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






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






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






45. 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.






46. 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.






47. 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.






48. 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






49. 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.






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