Class QuerySet
Represent a lazy database lookup for a set of objects.
Declaration
class QuerySet
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Methods
▷ def __deepcopy__(self, memo) Don't populate the QuerySet's cache.
▷ def __getitem__(self, k) Retrieve an item or slice from the set of results.
▷ def __init__(self, model=None, query=None, using=None, hints=None) ▶ def __iter__(self) The queryset iterator protocol uses three nested iterators in the
default case:
1. sql.compiler.execute_sql()
- Returns 100 rows at time (constants.GET_ITERATOR_CHUNK_SIZE)
using cursor.fetchmany(). This part is responsible for
doing some column masking, and returning the rows in chunks.
2. sql.compiler.results_iter()
- Returns one row at time. At this point the rows are still just
tuples. In some cases the return values are converted to
Python values at this location.
3. self.iterator()
- Responsible for turning the rows into model objects.▶ def aggregate(self, *args, **kwargs) Return a dictionary containing the calculations (aggregation) over the current queryset.
If args is present the expression is passed as a kwarg using
the Aggregate object's default alias.
▷ def alias(self, *args, **kwargs) Return a query set with added aliases for extra data or aggregations.
▷ def all(self) Return a new QuerySet that is a copy of the current one. This allows a QuerySet to proxy for a model manager in some cases.
▷ def annotate(self, *args, **kwargs) Return a query set in which the returned objects have been annotated with extra data or aggregations.
▶ def bulk_create(self, objs, batch_size=None, ignore_conflicts=False) Insert each of the instances into the database. Do *not* call
save() on each of the instances, do not send any pre/post_save
signals, and do not set the primary key attribute if it is an
autoincrement field (except if features.can_return_rows_from_bulk_insert=True).
Multi-table models are not supported.
▷ def bulk_update(self, objs, fields, batch_size=None) Update the given fields in each of the given objects in the database.
▶ def complex_filter(self, filter_obj) Return a new QuerySet instance with filter_obj added to the filters.
filter_obj can be a Q object or a dictionary of keyword lookup
arguments.
This exists to support framework features such as 'limit_choices_to',
and usually it will be more natural to use other methods.
▶ def count(self) Perform a SELECT COUNT() and return the number of records as an integer.
If the QuerySet is already fully cached, return the length of the
cached results set to avoid multiple SELECT COUNT(*) calls.
▷ def create(self, **kwargs) Create a new object with the given kwargs, saving it to the database and returning the created object.
▷ def dates(self, field_name, kind, order='ASC') Return a list of date objects representing all available dates for the given field_name, scoped to 'kind'.
▷ def datetimes(self, field_name, kind, order='ASC', tzinfo=None, is_dst=None) Return a list of datetime objects representing all available datetimes for the given field_name, scoped to 'kind'.
▷ def db(self) @property Return the database used if this query is executed now.
▶ def defer(self, *fields) Defer the loading of data for certain fields until they are accessed.
Add the set of deferred fields to any existing set of deferred fields.
The only exception to this is if None is passed in as the only
parameter, in which case removal all deferrals.
▷ def delete(self) Delete the records in the current QuerySet.
▷ def distinct(self, *field_names) Return a new QuerySet instance that will select only distinct results.
▷ def exclude(self, *args, **kwargs) Return a new QuerySet instance with NOT (args) ANDed to the existing set.
▷ def explain(self, *, format=None, **options) ▶ def extra(self, select=None, where=None, params=None, tables=None, order_by=None, ...) Add extra SQL fragments to the query.
▷ def filter(self, *args, **kwargs) Return a new QuerySet instance with the args ANDed to the existing set.
▷ def first(self) Return the first object of a query or None if no match is found.
▷ def get(self, *args, **kwargs) Perform the query and return a single object matching the given keyword arguments.
▷ def get_or_create(self, defaults=None, **kwargs) Look up an object with the given kwargs, creating one if necessary. Return a tuple of (object, created), where created is a boolean specifying whether an object was created.
▷ def in_bulk(self, id_list=None, *, field_name='pk') Return a dictionary mapping each of the given IDs to the object with that ID. If `id_list` isn't provided, evaluate the entire QuerySet.
▷ def iterator(self, chunk_size=2000) An iterator over the results from applying this QuerySet to the database.
▷ def last(self) Return the last object of a query or None if no match is found.
▷ def none(self) Return an empty QuerySet.
▷ def only(self, *fields) Essentially, the opposite of defer(). Only the fields passed into this method and that are not already specified as deferred are loaded immediately when the queryset is evaluated.
▷ def order_by(self, *field_names) Return a new QuerySet instance with the ordering changed.
▷ def ordered(self) @property Return True if the QuerySet is ordered -- i.e. has an order_by() clause or a default ordering on the model (or is empty).
@property
def ordered(self)
▶ def prefetch_related(self, *lookups) Return a new QuerySet instance that will prefetch the specified Many-To-One and Many-To-Many related objects when the QuerySet is evaluated.
▷ def query(self) @property ▷ def query(self, value) @query.setter @query.setter
def query(
self,
value,
)
▷ def raw(self, raw_query, params=None, translations=None, using=None) ▷ def reverse(self) Reverse the ordering of the QuerySet.
▷ def select_for_update(self, nowait=False, skip_locked=False, of=(), no_key=False) Return a new QuerySet instance that will select objects with a FOR UPDATE lock.
▶ def select_related(self, *fields) Return a new QuerySet instance that will select related objects.
▷ def union(self, *other_qs, all=False) ▷ def update(self, **kwargs) Update all elements in the current QuerySet, setting all the given fields to the appropriate values.
▶ def update_or_create(self, defaults=None, **kwargs) Look up an object with the given kwargs, updating one with defaults
if it exists, otherwise create a new one.
Return a tuple (object, created), where created is a boolean
specifying whether an object was created.
▷ def using(self, alias) Select which database this QuerySet should execute against.
▷ def values(self, *fields, **expressions) ▷ def values_list(self, *fields, flat=False, named=False)
Reexports