909 lines
38 KiB
Python
909 lines
38 KiB
Python
from django.db import backend, connection, transaction
|
|
from django.db.models.fields import DateField, FieldDoesNotExist
|
|
from django.db.models import signals
|
|
from django.dispatch import dispatcher
|
|
from django.utils.datastructures import SortedDict
|
|
|
|
import operator
|
|
|
|
# For Python 2.3
|
|
if not hasattr(__builtins__, 'set'):
|
|
from sets import Set as set
|
|
|
|
LOOKUP_SEPARATOR = '__'
|
|
|
|
# Size of each "chunk" for get_iterator calls.
|
|
# Larger values are slightly faster at the expense of more storage space.
|
|
GET_ITERATOR_CHUNK_SIZE = 100
|
|
|
|
####################
|
|
# HELPER FUNCTIONS #
|
|
####################
|
|
|
|
# Django currently supports two forms of ordering.
|
|
# Form 1 (deprecated) example:
|
|
# order_by=(('pub_date', 'DESC'), ('headline', 'ASC'), (None, 'RANDOM'))
|
|
# Form 2 (new-style) example:
|
|
# order_by=('-pub_date', 'headline', '?')
|
|
# Form 1 is deprecated and will no longer be supported for Django's first
|
|
# official release. The following code converts from Form 1 to Form 2.
|
|
|
|
LEGACY_ORDERING_MAPPING = {'ASC': '_', 'DESC': '-_', 'RANDOM': '?'}
|
|
|
|
def handle_legacy_orderlist(order_list):
|
|
if not order_list or isinstance(order_list[0], basestring):
|
|
return order_list
|
|
else:
|
|
import warnings
|
|
new_order_list = [LEGACY_ORDERING_MAPPING[j.upper()].replace('_', str(i)) for i, j in order_list]
|
|
warnings.warn("%r ordering syntax is deprecated. Use %r instead." % (order_list, new_order_list), DeprecationWarning)
|
|
return new_order_list
|
|
|
|
def orderfield2column(f, opts):
|
|
try:
|
|
return opts.get_field(f, False).column
|
|
except FieldDoesNotExist:
|
|
return f
|
|
|
|
def orderlist2sql(order_list, opts, prefix=''):
|
|
if prefix.endswith('.'):
|
|
prefix = backend.quote_name(prefix[:-1]) + '.'
|
|
output = []
|
|
for f in handle_legacy_orderlist(order_list):
|
|
if f.startswith('-'):
|
|
output.append('%s%s DESC' % (prefix, backend.quote_name(orderfield2column(f[1:], opts))))
|
|
elif f == '?':
|
|
output.append(backend.get_random_function_sql())
|
|
else:
|
|
output.append('%s%s ASC' % (prefix, backend.quote_name(orderfield2column(f, opts))))
|
|
return ', '.join(output)
|
|
|
|
def quote_only_if_word(word):
|
|
if ' ' in word:
|
|
return word
|
|
else:
|
|
return backend.quote_name(word)
|
|
|
|
class QuerySet(object):
|
|
"Represents a lazy database lookup for a set of objects"
|
|
def __init__(self, model=None):
|
|
self.model = model
|
|
self._filters = Q()
|
|
self._order_by = None # Ordering, e.g. ('date', '-name'). If None, use model's ordering.
|
|
self._select_related = False # Whether to fill cache for related objects.
|
|
self._distinct = False # Whether the query should use SELECT DISTINCT.
|
|
self._select = {} # Dictionary of attname -> SQL.
|
|
self._where = [] # List of extra WHERE clauses to use.
|
|
self._params = [] # List of params to use for extra WHERE clauses.
|
|
self._tables = [] # List of extra tables to use.
|
|
self._offset = None # OFFSET clause
|
|
self._limit = None # LIMIT clause
|
|
self._result_cache = None
|
|
|
|
########################
|
|
# PYTHON MAGIC METHODS #
|
|
########################
|
|
|
|
def __repr__(self):
|
|
return repr(self._get_data())
|
|
|
|
def __len__(self):
|
|
return len(self._get_data())
|
|
|
|
def __iter__(self):
|
|
return iter(self._get_data())
|
|
|
|
def __getitem__(self, k):
|
|
"Retrieve an item or slice from the set of results."
|
|
if self._result_cache is None:
|
|
if isinstance(k, slice):
|
|
# Offset:
|
|
if self._offset is None:
|
|
offset = k.start
|
|
elif k.start is None:
|
|
offset = self._offset
|
|
else:
|
|
offset = self._offset + k.start
|
|
# Now adjust offset to the bounds of any existing limit:
|
|
if self._limit is not None and k.start is not None:
|
|
limit = self._limit - k.start
|
|
else:
|
|
limit = self._limit
|
|
|
|
# Limit:
|
|
if k.stop is not None and k.start is not None:
|
|
if limit is None:
|
|
limit = k.stop - k.start
|
|
else:
|
|
limit = min((k.stop - k.start), limit)
|
|
else:
|
|
if limit is None:
|
|
limit = k.stop
|
|
else:
|
|
if k.stop is not None:
|
|
limit = min(k.stop, limit)
|
|
|
|
if k.step is None:
|
|
return self._clone(_offset=offset, _limit=limit)
|
|
else:
|
|
return list(self._clone(_offset=offset, _limit=limit))[::k.step]
|
|
else:
|
|
try:
|
|
return list(self._clone(_offset=k, _limit=1))[0]
|
|
except self.model.DoesNotExist, e:
|
|
raise IndexError, e.args
|
|
else:
|
|
return self._result_cache[k]
|
|
|
|
def __and__(self, other):
|
|
combined = self._combine(other)
|
|
combined._filters = self._filters & other._filters
|
|
return combined
|
|
|
|
def __or__(self, other):
|
|
combined = self._combine(other)
|
|
combined._filters = self._filters | other._filters
|
|
return combined
|
|
|
|
####################################
|
|
# METHODS THAT DO DATABASE QUERIES #
|
|
####################################
|
|
|
|
def iterator(self):
|
|
"Performs the SELECT database lookup of this QuerySet."
|
|
# self._select is a dictionary, and dictionaries' key order is
|
|
# undefined, so we convert it to a list of tuples.
|
|
extra_select = self._select.items()
|
|
|
|
cursor = connection.cursor()
|
|
select, sql, params = self._get_sql_clause()
|
|
cursor.execute("SELECT " + (self._distinct and "DISTINCT " or "") + ",".join(select) + sql, params)
|
|
fill_cache = self._select_related
|
|
index_end = len(self.model._meta.fields)
|
|
while 1:
|
|
rows = cursor.fetchmany(GET_ITERATOR_CHUNK_SIZE)
|
|
if not rows:
|
|
raise StopIteration
|
|
for row in rows:
|
|
if fill_cache:
|
|
obj, index_end = get_cached_row(self.model, row, 0)
|
|
else:
|
|
obj = self.model(*row[:index_end])
|
|
for i, k in enumerate(extra_select):
|
|
setattr(obj, k[0], row[index_end+i])
|
|
yield obj
|
|
|
|
def count(self):
|
|
"Performs a SELECT COUNT() and returns the number of records as an integer."
|
|
counter = self._clone()
|
|
counter._order_by = ()
|
|
counter._offset = None
|
|
counter._limit = None
|
|
counter._select_related = False
|
|
select, sql, params = counter._get_sql_clause()
|
|
cursor = connection.cursor()
|
|
if self._distinct:
|
|
id_col = "%s.%s" % (backend.quote_name(self.model._meta.db_table),
|
|
backend.quote_name(self.model._meta.pk.column))
|
|
cursor.execute("SELECT COUNT(DISTINCT(%s))" % id_col + sql, params)
|
|
else:
|
|
cursor.execute("SELECT COUNT(*)" + sql, params)
|
|
return cursor.fetchone()[0]
|
|
|
|
def get(self, *args, **kwargs):
|
|
"Performs the SELECT and returns a single object matching the given keyword arguments."
|
|
clone = self.filter(*args, **kwargs)
|
|
# clean up SQL by removing unneeded ORDER BY
|
|
if not clone._order_by:
|
|
clone._order_by = ()
|
|
obj_list = list(clone)
|
|
if len(obj_list) < 1:
|
|
raise self.model.DoesNotExist, "%s matching query does not exist." % self.model._meta.object_name
|
|
assert len(obj_list) == 1, "get() returned more than one %s -- it returned %s! Lookup parameters were %s" % (self.model._meta.object_name, len(obj_list), kwargs)
|
|
return obj_list[0]
|
|
|
|
def latest(self, field_name=None):
|
|
"""
|
|
Returns the latest object, according to the model's 'get_latest_by'
|
|
option or optional given field_name.
|
|
"""
|
|
latest_by = field_name or self.model._meta.get_latest_by
|
|
assert bool(latest_by), "latest() requires either a field_name parameter or 'get_latest_by' in the model"
|
|
assert self._limit is None and self._offset is None, \
|
|
"Cannot change a query once a slice has been taken."
|
|
return self._clone(_limit=1, _order_by=('-'+latest_by,)).get()
|
|
|
|
def in_bulk(self, id_list):
|
|
"""
|
|
Returns a dictionary mapping each of the given IDs to the object with
|
|
that ID.
|
|
"""
|
|
assert self._limit is None and self._offset is None, \
|
|
"Cannot use 'limit' or 'offset' with in_bulk"
|
|
assert isinstance(id_list, (tuple, list)), "in_bulk() must be provided with a list of IDs."
|
|
id_list = list(id_list)
|
|
if id_list == []:
|
|
return {}
|
|
qs = self._clone()
|
|
qs._where.append("%s.%s IN (%s)" % (backend.quote_name(self.model._meta.db_table), backend.quote_name(self.model._meta.pk.column), ",".join(['%s'] * len(id_list))))
|
|
qs._params.extend(id_list)
|
|
return dict([(obj._get_pk_val(), obj) for obj in qs.iterator()])
|
|
|
|
def delete(self):
|
|
"""
|
|
Deletes the records in the current QuerySet.
|
|
"""
|
|
assert self._limit is None and self._offset is None, \
|
|
"Cannot use 'limit' or 'offset' with delete."
|
|
|
|
del_query = self._clone()
|
|
|
|
# disable non-supported fields
|
|
del_query._select_related = False
|
|
del_query._order_by = []
|
|
|
|
# Delete objects in chunks to prevent an the list of
|
|
# related objects from becoming too long
|
|
more_objects = True
|
|
while more_objects:
|
|
# Collect all the objects to be deleted in this chunk, and all the objects
|
|
# that are related to the objects that are to be deleted
|
|
seen_objs = SortedDict()
|
|
more_objects = False
|
|
for object in del_query[0:GET_ITERATOR_CHUNK_SIZE]:
|
|
more_objects = True
|
|
object._collect_sub_objects(seen_objs)
|
|
|
|
# If one or more objects were found, delete them.
|
|
# Otherwise, stop looping.
|
|
if more_objects:
|
|
delete_objects(seen_objs)
|
|
|
|
# Clear the result cache, in case this QuerySet gets reused.
|
|
self._result_cache = None
|
|
delete.alters_data = True
|
|
|
|
##################################################
|
|
# PUBLIC METHODS THAT RETURN A QUERYSET SUBCLASS #
|
|
##################################################
|
|
|
|
def values(self, *fields):
|
|
return self._clone(klass=ValuesQuerySet, _fields=fields)
|
|
|
|
def dates(self, field_name, kind, order='ASC'):
|
|
"""
|
|
Returns a list of datetime objects representing all available dates
|
|
for the given field_name, scoped to 'kind'.
|
|
"""
|
|
assert kind in ("month", "year", "day"), "'kind' must be one of 'year', 'month' or 'day'."
|
|
assert order in ('ASC', 'DESC'), "'order' must be either 'ASC' or 'DESC'."
|
|
# Let the FieldDoesNotExist exception propagate.
|
|
field = self.model._meta.get_field(field_name, many_to_many=False)
|
|
assert isinstance(field, DateField), "%r isn't a DateField." % field_name
|
|
return self._clone(klass=DateQuerySet, _field=field, _kind=kind, _order=order)
|
|
|
|
##################################################################
|
|
# PUBLIC METHODS THAT ALTER ATTRIBUTES AND RETURN A NEW QUERYSET #
|
|
##################################################################
|
|
|
|
def filter(self, *args, **kwargs):
|
|
"Returns a new QuerySet instance with the args ANDed to the existing set."
|
|
return self._filter_or_exclude(Q, *args, **kwargs)
|
|
|
|
def exclude(self, *args, **kwargs):
|
|
"Returns a new QuerySet instance with NOT (args) ANDed to the existing set."
|
|
return self._filter_or_exclude(QNot, *args, **kwargs)
|
|
|
|
def _filter_or_exclude(self, qtype, *args, **kwargs):
|
|
if len(args) > 0 or len(kwargs) > 0:
|
|
assert self._limit is None and self._offset is None, \
|
|
"Cannot filter a query once a slice has been taken."
|
|
|
|
clone = self._clone()
|
|
if len(kwargs) > 0:
|
|
clone._filters = clone._filters & qtype(**kwargs)
|
|
if len(args) > 0:
|
|
clone._filters = clone._filters & reduce(operator.and_, args)
|
|
return clone
|
|
|
|
def complex_filter(self, filter_obj):
|
|
"""Returns a new QuerySet instance with filter_obj added to the filters.
|
|
filter_obj can be a Q object (has 'get_sql' method) 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.
|
|
if hasattr(filter_obj, 'get_sql'):
|
|
return self._filter_or_exclude(None, filter_obj)
|
|
else:
|
|
return self._filter_or_exclude(Q, **filter_obj)
|
|
|
|
def select_related(self, true_or_false=True):
|
|
"Returns a new QuerySet instance with '_select_related' modified."
|
|
return self._clone(_select_related=true_or_false)
|
|
|
|
def order_by(self, *field_names):
|
|
"Returns a new QuerySet instance with the ordering changed."
|
|
assert self._limit is None and self._offset is None, \
|
|
"Cannot reorder a query once a slice has been taken."
|
|
return self._clone(_order_by=field_names)
|
|
|
|
def distinct(self, true_or_false=True):
|
|
"Returns a new QuerySet instance with '_distinct' modified."
|
|
return self._clone(_distinct=true_or_false)
|
|
|
|
def extra(self, select=None, where=None, params=None, tables=None):
|
|
assert self._limit is None and self._offset is None, \
|
|
"Cannot change a query once a slice has been taken"
|
|
clone = self._clone()
|
|
if select: clone._select.update(select)
|
|
if where: clone._where.extend(where)
|
|
if params: clone._params.extend(params)
|
|
if tables: clone._tables.extend(tables)
|
|
return clone
|
|
|
|
###################
|
|
# PRIVATE METHODS #
|
|
###################
|
|
|
|
def _clone(self, klass=None, **kwargs):
|
|
if klass is None:
|
|
klass = self.__class__
|
|
c = klass()
|
|
c.model = self.model
|
|
c._filters = self._filters
|
|
c._order_by = self._order_by
|
|
c._select_related = self._select_related
|
|
c._distinct = self._distinct
|
|
c._select = self._select.copy()
|
|
c._where = self._where[:]
|
|
c._params = self._params[:]
|
|
c._tables = self._tables[:]
|
|
c._offset = self._offset
|
|
c._limit = self._limit
|
|
c.__dict__.update(kwargs)
|
|
return c
|
|
|
|
def _combine(self, other):
|
|
assert self._limit is None and self._offset is None \
|
|
and other._limit is None and other._offset is None, \
|
|
"Cannot combine queries once a slice has been taken."
|
|
assert self._distinct == other._distinct, \
|
|
"Cannot combine a unique query with a non-unique query"
|
|
# use 'other's order by
|
|
# (so that A.filter(args1) & A.filter(args2) does the same as
|
|
# A.filter(args1).filter(args2)
|
|
combined = other._clone()
|
|
# If 'self' is ordered and 'other' isn't, propagate 'self's ordering
|
|
if (self._order_by is not None and len(self._order_by) > 0) and \
|
|
(combined._order_by is None or len(combined._order_by) == 0):
|
|
combined._order_by = self._order_by
|
|
return combined
|
|
|
|
def _get_data(self):
|
|
if self._result_cache is None:
|
|
self._result_cache = list(self.iterator())
|
|
return self._result_cache
|
|
|
|
def _get_sql_clause(self):
|
|
opts = self.model._meta
|
|
|
|
# Construct the fundamental parts of the query: SELECT X FROM Y WHERE Z.
|
|
select = ["%s.%s" % (backend.quote_name(opts.db_table), backend.quote_name(f.column)) for f in opts.fields]
|
|
tables = [quote_only_if_word(t) for t in self._tables]
|
|
joins = SortedDict()
|
|
where = self._where[:]
|
|
params = self._params[:]
|
|
|
|
# Convert self._filters into SQL.
|
|
tables2, joins2, where2, params2 = self._filters.get_sql(opts)
|
|
tables.extend(tables2)
|
|
joins.update(joins2)
|
|
where.extend(where2)
|
|
params.extend(params2)
|
|
|
|
# Add additional tables and WHERE clauses based on select_related.
|
|
if self._select_related:
|
|
fill_table_cache(opts, select, tables, where, opts.db_table, [opts.db_table])
|
|
|
|
# Add any additional SELECTs.
|
|
if self._select:
|
|
select.extend(['(%s) AS %s' % (quote_only_if_word(s[1]), backend.quote_name(s[0])) for s in self._select.items()])
|
|
|
|
# Start composing the body of the SQL statement.
|
|
sql = [" FROM", backend.quote_name(opts.db_table)]
|
|
|
|
# Compose the join dictionary into SQL describing the joins.
|
|
if joins:
|
|
sql.append(" ".join(["%s %s AS %s ON %s" % (join_type, table, alias, condition)
|
|
for (alias, (table, join_type, condition)) in joins.items()]))
|
|
|
|
# Compose the tables clause into SQL.
|
|
if tables:
|
|
sql.append(", " + ", ".join(tables))
|
|
|
|
# Compose the where clause into SQL.
|
|
if where:
|
|
sql.append(where and "WHERE " + " AND ".join(where))
|
|
|
|
# ORDER BY clause
|
|
order_by = []
|
|
if self._order_by is not None:
|
|
ordering_to_use = self._order_by
|
|
else:
|
|
ordering_to_use = opts.ordering
|
|
for f in handle_legacy_orderlist(ordering_to_use):
|
|
if f == '?': # Special case.
|
|
order_by.append(backend.get_random_function_sql())
|
|
else:
|
|
if f.startswith('-'):
|
|
col_name = f[1:]
|
|
order = "DESC"
|
|
else:
|
|
col_name = f
|
|
order = "ASC"
|
|
if "." in col_name:
|
|
table_prefix, col_name = col_name.split('.', 1)
|
|
table_prefix = backend.quote_name(table_prefix) + '.'
|
|
else:
|
|
# Use the database table as a column prefix if it wasn't given,
|
|
# and if the requested column isn't a custom SELECT.
|
|
if "." not in col_name and col_name not in (self._select or ()):
|
|
table_prefix = backend.quote_name(opts.db_table) + '.'
|
|
else:
|
|
table_prefix = ''
|
|
order_by.append('%s%s %s' % (table_prefix, backend.quote_name(orderfield2column(col_name, opts)), order))
|
|
if order_by:
|
|
sql.append("ORDER BY " + ", ".join(order_by))
|
|
|
|
# LIMIT and OFFSET clauses
|
|
if self._limit is not None:
|
|
sql.append("%s " % backend.get_limit_offset_sql(self._limit, self._offset))
|
|
else:
|
|
assert self._offset is None, "'offset' is not allowed without 'limit'"
|
|
|
|
return select, " ".join(sql), params
|
|
|
|
class ValuesQuerySet(QuerySet):
|
|
def iterator(self):
|
|
# select_related and select aren't supported in values().
|
|
self._select_related = False
|
|
self._select = {}
|
|
|
|
# self._fields is a list of field names to fetch.
|
|
if self._fields:
|
|
columns = [self.model._meta.get_field(f, many_to_many=False).column for f in self._fields]
|
|
field_names = self._fields
|
|
else: # Default to all fields.
|
|
columns = [f.column for f in self.model._meta.fields]
|
|
field_names = [f.attname for f in self.model._meta.fields]
|
|
|
|
cursor = connection.cursor()
|
|
select, sql, params = self._get_sql_clause()
|
|
select = ['%s.%s' % (backend.quote_name(self.model._meta.db_table), backend.quote_name(c)) for c in columns]
|
|
cursor.execute("SELECT " + (self._distinct and "DISTINCT " or "") + ",".join(select) + sql, params)
|
|
while 1:
|
|
rows = cursor.fetchmany(GET_ITERATOR_CHUNK_SIZE)
|
|
if not rows:
|
|
raise StopIteration
|
|
for row in rows:
|
|
yield dict(zip(field_names, row))
|
|
|
|
def _clone(self, klass=None, **kwargs):
|
|
c = super(ValuesQuerySet, self)._clone(klass, **kwargs)
|
|
c._fields = self._fields[:]
|
|
return c
|
|
|
|
class DateQuerySet(QuerySet):
|
|
def iterator(self):
|
|
from django.db.backends.util import typecast_timestamp
|
|
self._order_by = () # Clear this because it'll mess things up otherwise.
|
|
if self._field.null:
|
|
self._where.append('%s.%s IS NOT NULL' % \
|
|
(backend.quote_name(self.model._meta.db_table), backend.quote_name(self._field.column)))
|
|
select, sql, params = self._get_sql_clause()
|
|
sql = 'SELECT %s %s GROUP BY 1 ORDER BY 1 %s' % \
|
|
(backend.get_date_trunc_sql(self._kind, '%s.%s' % (backend.quote_name(self.model._meta.db_table),
|
|
backend.quote_name(self._field.column))), sql, self._order)
|
|
cursor = connection.cursor()
|
|
cursor.execute(sql, params)
|
|
# We have to manually run typecast_timestamp(str()) on the results, because
|
|
# MySQL doesn't automatically cast the result of date functions as datetime
|
|
# objects -- MySQL returns the values as strings, instead.
|
|
return [typecast_timestamp(str(row[0])) for row in cursor.fetchall()]
|
|
|
|
def _clone(self, klass=None, **kwargs):
|
|
c = super(DateQuerySet, self)._clone(klass, **kwargs)
|
|
c._field = self._field
|
|
c._kind = self._kind
|
|
c._order = self._order
|
|
return c
|
|
|
|
class QOperator:
|
|
"Base class for QAnd and QOr"
|
|
def __init__(self, *args):
|
|
self.args = args
|
|
|
|
def get_sql(self, opts):
|
|
tables, joins, where, params = [], SortedDict(), [], []
|
|
for val in self.args:
|
|
tables2, joins2, where2, params2 = val.get_sql(opts)
|
|
tables.extend(tables2)
|
|
joins.update(joins2)
|
|
where.extend(where2)
|
|
params.extend(params2)
|
|
if where:
|
|
return tables, joins, ['(%s)' % self.operator.join(where)], params
|
|
return tables, joins, [], params
|
|
|
|
class QAnd(QOperator):
|
|
"Encapsulates a combined query that uses 'AND'."
|
|
operator = ' AND '
|
|
def __or__(self, other):
|
|
return QOr(self, other)
|
|
|
|
def __and__(self, other):
|
|
if isinstance(other, QAnd):
|
|
return QAnd(*(self.args+other.args))
|
|
elif isinstance(other, (Q, QOr)):
|
|
return QAnd(*(self.args+(other,)))
|
|
else:
|
|
raise TypeError, other
|
|
|
|
class QOr(QOperator):
|
|
"Encapsulates a combined query that uses 'OR'."
|
|
operator = ' OR '
|
|
def __and__(self, other):
|
|
return QAnd(self, other)
|
|
|
|
def __or__(self, other):
|
|
if isinstance(other, QOr):
|
|
return QOr(*(self.args+other.args))
|
|
elif isinstance(other, (Q, QAnd)):
|
|
return QOr(*(self.args+(other,)))
|
|
else:
|
|
raise TypeError, other
|
|
|
|
class Q(object):
|
|
"Encapsulates queries as objects that can be combined logically."
|
|
def __init__(self, **kwargs):
|
|
self.kwargs = kwargs
|
|
|
|
def __and__(self, other):
|
|
return QAnd(self, other)
|
|
|
|
def __or__(self, other):
|
|
return QOr(self, other)
|
|
|
|
def get_sql(self, opts):
|
|
return parse_lookup(self.kwargs.items(), opts)
|
|
|
|
class QNot(Q):
|
|
"Encapsulates NOT (...) queries as objects"
|
|
|
|
def get_sql(self, opts):
|
|
tables, joins, where, params = super(QNot, self).get_sql(opts)
|
|
where2 = ['(NOT (%s))' % " AND ".join(where)]
|
|
return tables, joins, where2, params
|
|
|
|
def get_where_clause(lookup_type, table_prefix, field_name, value):
|
|
if table_prefix.endswith('.'):
|
|
table_prefix = backend.quote_name(table_prefix[:-1])+'.'
|
|
field_name = backend.quote_name(field_name)
|
|
try:
|
|
return '%s%s %s' % (table_prefix, field_name, (backend.OPERATOR_MAPPING[lookup_type] % '%s'))
|
|
except KeyError:
|
|
pass
|
|
if lookup_type == 'in':
|
|
return '%s%s IN (%s)' % (table_prefix, field_name, ','.join(['%s' for v in value]))
|
|
elif lookup_type == 'range':
|
|
return '%s%s BETWEEN %%s AND %%s' % (table_prefix, field_name)
|
|
elif lookup_type in ('year', 'month', 'day'):
|
|
return "%s = %%s" % backend.get_date_extract_sql(lookup_type, table_prefix + field_name)
|
|
elif lookup_type == 'isnull':
|
|
return "%s%s IS %sNULL" % (table_prefix, field_name, (not value and 'NOT ' or ''))
|
|
raise TypeError, "Got invalid lookup_type: %s" % repr(lookup_type)
|
|
|
|
def get_cached_row(klass, row, index_start):
|
|
"Helper function that recursively returns an object with cache filled"
|
|
index_end = index_start + len(klass._meta.fields)
|
|
obj = klass(*row[index_start:index_end])
|
|
for f in klass._meta.fields:
|
|
if f.rel and not f.null:
|
|
rel_obj, index_end = get_cached_row(f.rel.to, row, index_end)
|
|
setattr(obj, f.get_cache_name(), rel_obj)
|
|
return obj, index_end
|
|
|
|
def fill_table_cache(opts, select, tables, where, old_prefix, cache_tables_seen):
|
|
"""
|
|
Helper function that recursively populates the select, tables and where (in
|
|
place) for fill-cache queries.
|
|
"""
|
|
for f in opts.fields:
|
|
if f.rel and not f.null:
|
|
db_table = f.rel.to._meta.db_table
|
|
if db_table not in cache_tables_seen:
|
|
tables.append(backend.quote_name(db_table))
|
|
else: # The table was already seen, so give it a table alias.
|
|
new_prefix = '%s%s' % (db_table, len(cache_tables_seen))
|
|
tables.append('%s %s' % (backend.quote_name(db_table), backend.quote_name(new_prefix)))
|
|
db_table = new_prefix
|
|
cache_tables_seen.append(db_table)
|
|
where.append('%s.%s = %s.%s' % \
|
|
(backend.quote_name(old_prefix), backend.quote_name(f.column),
|
|
backend.quote_name(db_table), backend.quote_name(f.rel.get_related_field().column)))
|
|
select.extend(['%s.%s' % (backend.quote_name(db_table), backend.quote_name(f2.column)) for f2 in f.rel.to._meta.fields])
|
|
fill_table_cache(f.rel.to._meta, select, tables, where, db_table, cache_tables_seen)
|
|
|
|
def parse_lookup(kwarg_items, opts):
|
|
# Helper function that handles converting API kwargs
|
|
# (e.g. "name__exact": "tom") to SQL.
|
|
|
|
# 'joins' is a sorted dictionary describing the tables that must be joined
|
|
# to complete the query. The dictionary is sorted because creation order
|
|
# is significant; it is a dictionary to ensure uniqueness of alias names.
|
|
#
|
|
# Each key-value pair follows the form
|
|
# alias: (table, join_type, condition)
|
|
# where
|
|
# alias is the AS alias for the joined table
|
|
# table is the actual table name to be joined
|
|
# join_type is the type of join (INNER JOIN, LEFT OUTER JOIN, etc)
|
|
# condition is the where-like statement over which narrows the join.
|
|
# alias will be derived from the lookup list name.
|
|
#
|
|
# At present, this method only every returns INNER JOINs; the option is
|
|
# there for others to implement custom Q()s, etc that return other join
|
|
# types.
|
|
tables, joins, where, params = [], SortedDict(), [], []
|
|
|
|
for kwarg, value in kwarg_items:
|
|
if value is not None:
|
|
path = kwarg.split(LOOKUP_SEPARATOR)
|
|
# Extract the last elements of the kwarg.
|
|
# The very-last is the clause (equals, like, etc).
|
|
# The second-last is the table column on which the clause is
|
|
# to be performed.
|
|
# The exceptions to this are:
|
|
# 1) "pk", which is an implicit id__exact;
|
|
# if we find "pk", make the clause "exact', and insert
|
|
# a dummy name of None, which we will replace when
|
|
# we know which table column to grab as the primary key.
|
|
# 2) If there is only one part, assume it to be an __exact
|
|
clause = path.pop()
|
|
if clause == 'pk':
|
|
clause = 'exact'
|
|
path.append(None)
|
|
elif len(path) == 0:
|
|
path.append(clause)
|
|
clause = 'exact'
|
|
|
|
if len(path) < 1:
|
|
raise TypeError, "Cannot parse keyword query %r" % kwarg
|
|
|
|
tables2, joins2, where2, params2 = lookup_inner(path, clause, value, opts, opts.db_table, None)
|
|
tables.extend(tables2)
|
|
joins.update(joins2)
|
|
where.extend(where2)
|
|
params.extend(params2)
|
|
return tables, joins, where, params
|
|
|
|
class FieldFound(Exception):
|
|
"Exception used to short circuit field-finding operations."
|
|
pass
|
|
|
|
def find_field(name, field_list, related_query):
|
|
"""
|
|
Finds a field with a specific name in a list of field instances.
|
|
Returns None if there are no matches, or several matches.
|
|
"""
|
|
if related_query:
|
|
matches = [f for f in field_list if f.field.related_query_name() == name]
|
|
else:
|
|
matches = [f for f in field_list if f.name == name]
|
|
if len(matches) != 1:
|
|
return None
|
|
return matches[0]
|
|
|
|
def lookup_inner(path, clause, value, opts, table, column):
|
|
tables, joins, where, params = [], SortedDict(), [], []
|
|
current_opts = opts
|
|
current_table = table
|
|
current_column = column
|
|
intermediate_table = None
|
|
join_required = False
|
|
|
|
name = path.pop(0)
|
|
# Has the primary key been requested? If so, expand it out
|
|
# to be the name of the current class' primary key
|
|
if name is None:
|
|
name = current_opts.pk.name
|
|
|
|
# Try to find the name in the fields associated with the current class
|
|
try:
|
|
# Does the name belong to a defined many-to-many field?
|
|
field = find_field(name, current_opts.many_to_many, False)
|
|
if field:
|
|
new_table = current_table + LOOKUP_SEPARATOR + name
|
|
new_opts = field.rel.to._meta
|
|
new_column = new_opts.pk.column
|
|
|
|
# Need to create an intermediate table join over the m2m table
|
|
# This process hijacks current_table/column to point to the
|
|
# intermediate table.
|
|
current_table = "m2m_" + new_table
|
|
intermediate_table = field.m2m_db_table()
|
|
join_column = field.m2m_reverse_name()
|
|
intermediate_column = field.m2m_column_name()
|
|
|
|
raise FieldFound
|
|
|
|
# Does the name belong to a reverse defined many-to-many field?
|
|
field = find_field(name, current_opts.get_all_related_many_to_many_objects(), True)
|
|
if field:
|
|
new_table = current_table + LOOKUP_SEPARATOR + name
|
|
new_opts = field.opts
|
|
new_column = new_opts.pk.column
|
|
|
|
# Need to create an intermediate table join over the m2m table.
|
|
# This process hijacks current_table/column to point to the
|
|
# intermediate table.
|
|
current_table = "m2m_" + new_table
|
|
intermediate_table = field.field.m2m_db_table()
|
|
join_column = field.field.m2m_column_name()
|
|
intermediate_column = field.field.m2m_reverse_name()
|
|
|
|
raise FieldFound
|
|
|
|
# Does the name belong to a one-to-many field?
|
|
field = find_field(name, current_opts.get_all_related_objects(), True)
|
|
if field:
|
|
new_table = table + LOOKUP_SEPARATOR + name
|
|
new_opts = field.opts
|
|
new_column = field.field.column
|
|
join_column = opts.pk.column
|
|
|
|
# 1-N fields MUST be joined, regardless of any other conditions.
|
|
join_required = True
|
|
|
|
raise FieldFound
|
|
|
|
# Does the name belong to a one-to-one, many-to-one, or regular field?
|
|
field = find_field(name, current_opts.fields, False)
|
|
if field:
|
|
if field.rel: # One-to-One/Many-to-one field
|
|
new_table = current_table + LOOKUP_SEPARATOR + name
|
|
new_opts = field.rel.to._meta
|
|
new_column = new_opts.pk.column
|
|
join_column = field.column
|
|
|
|
raise FieldFound
|
|
|
|
except FieldFound: # Match found, loop has been shortcut.
|
|
pass
|
|
except: # Any other exception; rethrow
|
|
raise
|
|
else: # No match found.
|
|
raise TypeError, "Cannot resolve keyword '%s' into field" % name
|
|
|
|
# Check to see if an intermediate join is required between current_table
|
|
# and new_table.
|
|
if intermediate_table:
|
|
joins[backend.quote_name(current_table)] = (
|
|
backend.quote_name(intermediate_table),
|
|
"LEFT OUTER JOIN",
|
|
"%s.%s = %s.%s" % \
|
|
(backend.quote_name(table),
|
|
backend.quote_name(current_opts.pk.column),
|
|
backend.quote_name(current_table),
|
|
backend.quote_name(intermediate_column))
|
|
)
|
|
|
|
if path:
|
|
if len(path) == 1 and path[0] in (new_opts.pk.name, None) \
|
|
and clause in ('exact', 'isnull') and not join_required:
|
|
# If the last name query is for a key, and the search is for
|
|
# isnull/exact, then the current (for N-1) or intermediate
|
|
# (for N-N) table can be used for the search - no need to join an
|
|
# extra table just to check the primary key.
|
|
new_table = current_table
|
|
else:
|
|
# There are 1 or more name queries pending, and we have ruled out
|
|
# any shortcuts; therefore, a join is required.
|
|
joins[backend.quote_name(new_table)] = (
|
|
backend.quote_name(new_opts.db_table),
|
|
"INNER JOIN",
|
|
"%s.%s = %s.%s" %
|
|
(backend.quote_name(current_table),
|
|
backend.quote_name(join_column),
|
|
backend.quote_name(new_table),
|
|
backend.quote_name(new_column))
|
|
)
|
|
# If we have made the join, we don't need to tell subsequent
|
|
# recursive calls about the column name we joined on.
|
|
join_column = None
|
|
|
|
# There are name queries remaining. Recurse deeper.
|
|
tables2, joins2, where2, params2 = lookup_inner(path, clause, value, new_opts, new_table, join_column)
|
|
|
|
tables.extend(tables2)
|
|
joins.update(joins2)
|
|
where.extend(where2)
|
|
params.extend(params2)
|
|
else:
|
|
# Evaluate clause on current table.
|
|
if name in (current_opts.pk.name, None) and clause in ('exact', 'isnull') and current_column:
|
|
# If this is an exact/isnull key search, and the last pass
|
|
# found/introduced a current/intermediate table that we can use to
|
|
# optimize the query, then use that column name.
|
|
column = current_column
|
|
else:
|
|
column = field.column
|
|
|
|
where.append(get_where_clause(clause, current_table + '.', column, value))
|
|
params.extend(field.get_db_prep_lookup(clause, value))
|
|
|
|
return tables, joins, where, params
|
|
|
|
def delete_objects(seen_objs):
|
|
"Iterate through a list of seen classes, and remove any instances that are referred to"
|
|
ordered_classes = seen_objs.keys()
|
|
ordered_classes.reverse()
|
|
|
|
cursor = connection.cursor()
|
|
|
|
for cls in ordered_classes:
|
|
seen_objs[cls] = seen_objs[cls].items()
|
|
seen_objs[cls].sort()
|
|
|
|
# Pre notify all instances to be deleted
|
|
for pk_val, instance in seen_objs[cls]:
|
|
dispatcher.send(signal=signals.pre_delete, sender=cls, instance=instance)
|
|
|
|
pk_list = [pk for pk,instance in seen_objs[cls]]
|
|
for related in cls._meta.get_all_related_many_to_many_objects():
|
|
for offset in range(0, len(pk_list), GET_ITERATOR_CHUNK_SIZE):
|
|
cursor.execute("DELETE FROM %s WHERE %s IN (%s)" % \
|
|
(backend.quote_name(related.field.m2m_db_table()),
|
|
backend.quote_name(related.field.m2m_reverse_name()),
|
|
','.join(['%s' for pk in pk_list[offset:offset+GET_ITERATOR_CHUNK_SIZE]])),
|
|
pk_list[offset:offset+GET_ITERATOR_CHUNK_SIZE])
|
|
for f in cls._meta.many_to_many:
|
|
for offset in range(0, len(pk_list), GET_ITERATOR_CHUNK_SIZE):
|
|
cursor.execute("DELETE FROM %s WHERE %s IN (%s)" % \
|
|
(backend.quote_name(f.m2m_db_table()),
|
|
backend.quote_name(f.m2m_column_name()),
|
|
','.join(['%s' for pk in pk_list[offset:offset+GET_ITERATOR_CHUNK_SIZE]])),
|
|
pk_list[offset:offset+GET_ITERATOR_CHUNK_SIZE])
|
|
for field in cls._meta.fields:
|
|
if field.rel and field.null and field.rel.to in seen_objs:
|
|
for offset in range(0, len(pk_list), GET_ITERATOR_CHUNK_SIZE):
|
|
cursor.execute("UPDATE %s SET %s=NULL WHERE %s IN (%s)" % \
|
|
(backend.quote_name(cls._meta.db_table),
|
|
backend.quote_name(field.column),
|
|
backend.quote_name(cls._meta.pk.column),
|
|
','.join(['%s' for pk in pk_list[offset:offset+GET_ITERATOR_CHUNK_SIZE]])),
|
|
pk_list[offset:offset+GET_ITERATOR_CHUNK_SIZE])
|
|
|
|
# Now delete the actual data
|
|
for cls in ordered_classes:
|
|
seen_objs[cls].reverse()
|
|
pk_list = [pk for pk,instance in seen_objs[cls]]
|
|
for offset in range(0, len(pk_list), GET_ITERATOR_CHUNK_SIZE):
|
|
cursor.execute("DELETE FROM %s WHERE %s IN (%s)" % \
|
|
(backend.quote_name(cls._meta.db_table),
|
|
backend.quote_name(cls._meta.pk.column),
|
|
','.join(['%s' for pk in pk_list[offset:offset+GET_ITERATOR_CHUNK_SIZE]])),
|
|
pk_list[offset:offset+GET_ITERATOR_CHUNK_SIZE])
|
|
|
|
# Last cleanup; set NULLs where there once was a reference to the object,
|
|
# NULL the primary key of the found objects, and perform post-notification.
|
|
for pk_val, instance in seen_objs[cls]:
|
|
for field in cls._meta.fields:
|
|
if field.rel and field.null and field.rel.to in seen_objs:
|
|
setattr(instance, field.attname, None)
|
|
|
|
setattr(instance, cls._meta.pk.attname, None)
|
|
dispatcher.send(signal=signals.post_delete, sender=cls, instance=instance)
|
|
|
|
transaction.commit_unless_managed()
|