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






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






3. Negation operator for Q objects.






4. 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()






5. 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






6. 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






7. 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






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






9. 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.






10. Returns the object matching the given lookup parameters






11. 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.


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






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






14. 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.






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






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






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






18. Fields are specified by these






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






20. 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.






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






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






23. This gives your model metadata.






24. 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.






25. 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






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






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






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






29. 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.






30. 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.






31. 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.






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






33. 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.






34. 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.






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






36. 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






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


38. Lookup type that returns results with a case-insensitive start sequence.






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






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






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






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






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


45. 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






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






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






48. (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.






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






50. 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.