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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. 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






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






3. 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.






4. 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.






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






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






7. 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






8. Lookup type that takes either True or False and corresponds to SQL queries of IS NULL and IS NOT NULL - respectively.






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






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






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






12. 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.






13. 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






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






15. 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.






16. Used to get a QuerySet for a model. This is called 'objects' by default.






17. 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






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






19. 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






20. 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.






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






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






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






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






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






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






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






28. 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.






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






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






31. Lookup type for date/datetime fields that finds an exact day match.






32. 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)






33. (1) These cannot be Python reserved words - because that would result in a Python syntax error. (2) These cannot contain more than one underscore in a row - due to the way Django's query lookup syntax works.






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






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






36. 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()






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






38. 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.






39. 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


40. 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.






41. 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.






42. This method returns tuples of values when iterated over. Each tuple contains the value from the respective field passed into the call to this method -- so the first item is the first field - etc.






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






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






45. 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






46. 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.






47. The database that will be used if this query is executed now






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. Lookup type that yields a case-insensitive match.






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