mirror of
https://github.com/django/django.git
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1124 lines
48 KiB
Python
1124 lines
48 KiB
Python
import datetime
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from django.conf import settings
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from django.core.exceptions import FieldError
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from django.db.backends.utils import truncate_name
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from django.db.models.constants import LOOKUP_SEP
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from django.db.models.query_utils import select_related_descend, QueryWrapper
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from django.db.models.sql.constants import (SINGLE, MULTI, ORDER_DIR,
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GET_ITERATOR_CHUNK_SIZE, SelectInfo)
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from django.db.models.sql.datastructures import EmptyResultSet
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from django.db.models.sql.expressions import SQLEvaluator
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from django.db.models.sql.query import get_order_dir, Query
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from django.db.utils import DatabaseError
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from django.utils import six
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from django.utils.six.moves import zip
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from django.utils import timezone
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class SQLCompiler(object):
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def __init__(self, query, connection, using):
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self.query = query
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self.connection = connection
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self.using = using
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self.quote_cache = {'*': '*'}
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# When ordering a queryset with distinct on a column not part of the
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# select set, the ordering column needs to be added to the select
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# clause. This information is needed both in SQL construction and
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# masking away the ordering selects from the returned row.
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self.ordering_aliases = []
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self.ordering_params = []
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def pre_sql_setup(self):
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"""
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Does any necessary class setup immediately prior to producing SQL. This
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is for things that can't necessarily be done in __init__ because we
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might not have all the pieces in place at that time.
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# TODO: after the query has been executed, the altered state should be
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# cleaned. We are not using a clone() of the query here.
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"""
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if not self.query.tables:
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self.query.join((None, self.query.get_meta().db_table, None))
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if (not self.query.select and self.query.default_cols and not
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self.query.included_inherited_models):
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self.query.setup_inherited_models()
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if self.query.select_related and not self.query.related_select_cols:
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self.fill_related_selections()
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def __call__(self, name):
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"""
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A wrapper around connection.ops.quote_name that doesn't quote aliases
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for table names. This avoids problems with some SQL dialects that treat
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quoted strings specially (e.g. PostgreSQL).
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"""
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if name in self.quote_cache:
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return self.quote_cache[name]
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if ((name in self.query.alias_map and name not in self.query.table_map) or
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name in self.query.extra_select):
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self.quote_cache[name] = name
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return name
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r = self.connection.ops.quote_name(name)
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self.quote_cache[name] = r
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return r
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def quote_name_unless_alias(self, name):
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"""
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A wrapper around connection.ops.quote_name that doesn't quote aliases
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for table names. This avoids problems with some SQL dialects that treat
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quoted strings specially (e.g. PostgreSQL).
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"""
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return self(name)
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def compile(self, node):
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vendor_impl = getattr(
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node, 'as_' + self.connection.vendor, None)
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if vendor_impl:
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return vendor_impl(self, self.connection)
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else:
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return node.as_sql(self, self.connection)
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def as_sql(self, with_limits=True, with_col_aliases=False):
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"""
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Creates the SQL for this query. Returns the SQL string and list of
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parameters.
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If 'with_limits' is False, any limit/offset information is not included
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in the query.
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"""
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if with_limits and self.query.low_mark == self.query.high_mark:
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return '', ()
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self.pre_sql_setup()
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# After executing the query, we must get rid of any joins the query
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# setup created. So, take note of alias counts before the query ran.
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# However we do not want to get rid of stuff done in pre_sql_setup(),
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# as the pre_sql_setup will modify query state in a way that forbids
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# another run of it.
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self.refcounts_before = self.query.alias_refcount.copy()
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out_cols, s_params = self.get_columns(with_col_aliases)
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ordering, o_params, ordering_group_by = self.get_ordering()
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distinct_fields = self.get_distinct()
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# This must come after 'select', 'ordering' and 'distinct' -- see
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# docstring of get_from_clause() for details.
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from_, f_params = self.get_from_clause()
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where, w_params = self.compile(self.query.where)
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having, h_params = self.compile(self.query.having)
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having_group_by = self.query.having.get_group_by_cols()
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params = []
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for val in six.itervalues(self.query.extra_select):
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params.extend(val[1])
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result = ['SELECT']
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if self.query.distinct:
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result.append(self.connection.ops.distinct_sql(distinct_fields))
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params.extend(o_params)
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result.append(', '.join(out_cols + self.ordering_aliases))
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params.extend(s_params)
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params.extend(self.ordering_params)
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result.append('FROM')
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result.extend(from_)
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params.extend(f_params)
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if where:
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result.append('WHERE %s' % where)
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params.extend(w_params)
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grouping, gb_params = self.get_grouping(having_group_by, ordering_group_by)
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if grouping:
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if distinct_fields:
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raise NotImplementedError(
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"annotate() + distinct(fields) not implemented.")
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if not ordering:
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ordering = self.connection.ops.force_no_ordering()
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result.append('GROUP BY %s' % ', '.join(grouping))
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params.extend(gb_params)
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if having:
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result.append('HAVING %s' % having)
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params.extend(h_params)
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if ordering:
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result.append('ORDER BY %s' % ', '.join(ordering))
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if with_limits:
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if self.query.high_mark is not None:
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result.append('LIMIT %d' % (self.query.high_mark - self.query.low_mark))
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if self.query.low_mark:
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if self.query.high_mark is None:
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val = self.connection.ops.no_limit_value()
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if val:
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result.append('LIMIT %d' % val)
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result.append('OFFSET %d' % self.query.low_mark)
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if self.query.select_for_update and self.connection.features.has_select_for_update:
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# If we've been asked for a NOWAIT query but the backend does not support it,
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# raise a DatabaseError otherwise we could get an unexpected deadlock.
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nowait = self.query.select_for_update_nowait
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if nowait and not self.connection.features.has_select_for_update_nowait:
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raise DatabaseError('NOWAIT is not supported on this database backend.')
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result.append(self.connection.ops.for_update_sql(nowait=nowait))
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# Finally do cleanup - get rid of the joins we created above.
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self.query.reset_refcounts(self.refcounts_before)
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return ' '.join(result), tuple(params)
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def as_nested_sql(self):
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"""
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Perform the same functionality as the as_sql() method, returning an
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SQL string and parameters. However, the alias prefixes are bumped
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beforehand (in a copy -- the current query isn't changed), and any
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ordering is removed if the query is unsliced.
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Used when nesting this query inside another.
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"""
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obj = self.query.clone()
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if obj.low_mark == 0 and obj.high_mark is None and not self.query.distinct_fields:
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# If there is no slicing in use, then we can safely drop all ordering
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obj.clear_ordering(True)
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return obj.get_compiler(connection=self.connection).as_sql()
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def get_columns(self, with_aliases=False):
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"""
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Returns the list of columns to use in the select statement, as well as
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a list any extra parameters that need to be included. If no columns
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have been specified, returns all columns relating to fields in the
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model.
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If 'with_aliases' is true, any column names that are duplicated
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(without the table names) are given unique aliases. This is needed in
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some cases to avoid ambiguity with nested queries.
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"""
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qn = self
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qn2 = self.connection.ops.quote_name
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result = ['(%s) AS %s' % (col[0], qn2(alias)) for alias, col in six.iteritems(self.query.extra_select)]
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params = []
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aliases = set(self.query.extra_select.keys())
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if with_aliases:
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col_aliases = aliases.copy()
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else:
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col_aliases = set()
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if self.query.select:
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only_load = self.deferred_to_columns()
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for col, _ in self.query.select:
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if isinstance(col, (list, tuple)):
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alias, column = col
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table = self.query.alias_map[alias].table_name
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if table in only_load and column not in only_load[table]:
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continue
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r = '%s.%s' % (qn(alias), qn(column))
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if with_aliases:
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if col[1] in col_aliases:
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c_alias = 'Col%d' % len(col_aliases)
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result.append('%s AS %s' % (r, c_alias))
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aliases.add(c_alias)
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col_aliases.add(c_alias)
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else:
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result.append('%s AS %s' % (r, qn2(col[1])))
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aliases.add(r)
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col_aliases.add(col[1])
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else:
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result.append(r)
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aliases.add(r)
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col_aliases.add(col[1])
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else:
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col_sql, col_params = self.compile(col)
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result.append(col_sql)
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params.extend(col_params)
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if hasattr(col, 'alias'):
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aliases.add(col.alias)
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col_aliases.add(col.alias)
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elif self.query.default_cols:
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cols, new_aliases = self.get_default_columns(with_aliases,
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col_aliases)
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result.extend(cols)
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aliases.update(new_aliases)
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max_name_length = self.connection.ops.max_name_length()
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for alias, aggregate in self.query.aggregate_select.items():
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agg_sql, agg_params = self.compile(aggregate)
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if alias is None:
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result.append(agg_sql)
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else:
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result.append('%s AS %s' % (agg_sql, qn(truncate_name(alias, max_name_length))))
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params.extend(agg_params)
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for (table, col), _ in self.query.related_select_cols:
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r = '%s.%s' % (qn(table), qn(col))
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if with_aliases and col in col_aliases:
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c_alias = 'Col%d' % len(col_aliases)
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result.append('%s AS %s' % (r, c_alias))
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aliases.add(c_alias)
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col_aliases.add(c_alias)
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else:
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result.append(r)
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aliases.add(r)
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col_aliases.add(col)
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self._select_aliases = aliases
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return result, params
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def get_default_columns(self, with_aliases=False, col_aliases=None,
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start_alias=None, opts=None, as_pairs=False, from_parent=None):
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"""
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Computes the default columns for selecting every field in the base
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model. Will sometimes be called to pull in related models (e.g. via
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select_related), in which case "opts" and "start_alias" will be given
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to provide a starting point for the traversal.
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Returns a list of strings, quoted appropriately for use in SQL
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directly, as well as a set of aliases used in the select statement (if
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'as_pairs' is True, returns a list of (alias, col_name) pairs instead
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of strings as the first component and None as the second component).
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"""
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result = []
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if opts is None:
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opts = self.query.get_meta()
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qn = self
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qn2 = self.connection.ops.quote_name
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aliases = set()
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only_load = self.deferred_to_columns()
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if not start_alias:
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start_alias = self.query.get_initial_alias()
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# The 'seen_models' is used to optimize checking the needed parent
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# alias for a given field. This also includes None -> start_alias to
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# be used by local fields.
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seen_models = {None: start_alias}
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for field, model in opts.get_concrete_fields_with_model():
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if from_parent and model is not None and issubclass(from_parent, model):
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# Avoid loading data for already loaded parents.
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continue
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alias = self.query.join_parent_model(opts, model, start_alias,
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seen_models)
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column = field.column
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for seen_model, seen_alias in seen_models.items():
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if seen_model and seen_alias == alias:
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ancestor_link = seen_model._meta.get_ancestor_link(model)
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if ancestor_link:
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column = ancestor_link.column
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break
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table = self.query.alias_map[alias].table_name
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if table in only_load and column not in only_load[table]:
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continue
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if as_pairs:
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result.append((alias, field))
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aliases.add(alias)
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continue
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if with_aliases and column in col_aliases:
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c_alias = 'Col%d' % len(col_aliases)
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result.append('%s.%s AS %s' % (qn(alias),
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qn2(column), c_alias))
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col_aliases.add(c_alias)
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aliases.add(c_alias)
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else:
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r = '%s.%s' % (qn(alias), qn2(column))
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result.append(r)
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aliases.add(r)
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if with_aliases:
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col_aliases.add(column)
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return result, aliases
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def get_distinct(self):
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"""
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Returns a quoted list of fields to use in DISTINCT ON part of the query.
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Note that this method can alter the tables in the query, and thus it
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must be called before get_from_clause().
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"""
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qn = self
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qn2 = self.connection.ops.quote_name
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result = []
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opts = self.query.get_meta()
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for name in self.query.distinct_fields:
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parts = name.split(LOOKUP_SEP)
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_, targets, alias, joins, path, _ = self._setup_joins(parts, opts, None)
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targets, alias, _ = self.query.trim_joins(targets, joins, path)
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for target in targets:
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result.append("%s.%s" % (qn(alias), qn2(target.column)))
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return result
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def get_ordering(self):
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"""
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Returns a tuple containing a list representing the SQL elements in the
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"order by" clause, and the list of SQL elements that need to be added
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to the GROUP BY clause as a result of the ordering.
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Also sets the ordering_aliases attribute on this instance to a list of
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extra aliases needed in the select.
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Determining the ordering SQL can change the tables we need to include,
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so this should be run *before* get_from_clause().
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"""
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if self.query.extra_order_by:
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ordering = self.query.extra_order_by
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elif not self.query.default_ordering:
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ordering = self.query.order_by
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else:
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ordering = (self.query.order_by
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or self.query.get_meta().ordering
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or [])
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qn = self
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qn2 = self.connection.ops.quote_name
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distinct = self.query.distinct
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select_aliases = self._select_aliases
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result = []
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group_by = []
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ordering_aliases = []
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if self.query.standard_ordering:
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asc, desc = ORDER_DIR['ASC']
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else:
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asc, desc = ORDER_DIR['DESC']
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# It's possible, due to model inheritance, that normal usage might try
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# to include the same field more than once in the ordering. We track
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# the table/column pairs we use and discard any after the first use.
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processed_pairs = set()
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params = []
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ordering_params = []
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# For plain DISTINCT queries any ORDER BY clause must appear
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# in SELECT clause.
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# http://www.postgresql.org/message-id/27009.1171559417@sss.pgh.pa.us
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must_append_to_select = distinct and not self.query.distinct_fields
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for pos, field in enumerate(ordering):
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if field == '?':
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result.append(self.connection.ops.random_function_sql())
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continue
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if isinstance(field, int):
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if field < 0:
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order = desc
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field = -field
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else:
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order = asc
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result.append('%s %s' % (field, order))
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group_by.append((str(field), []))
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continue
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col, order = get_order_dir(field, asc)
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if col in self.query.aggregate_select:
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result.append('%s %s' % (qn(col), order))
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continue
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if '.' in field:
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# This came in through an extra(order_by=...) addition. Pass it
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# on verbatim.
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table, col = col.split('.', 1)
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if (table, col) not in processed_pairs:
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elt = '%s.%s' % (qn(table), col)
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processed_pairs.add((table, col))
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if not must_append_to_select or elt in select_aliases:
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result.append('%s %s' % (elt, order))
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group_by.append((elt, []))
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elif not self.query._extra or get_order_dir(field)[0] not in self.query._extra:
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# 'col' is of the form 'field' or 'field1__field2' or
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# '-field1__field2__field', etc.
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for table, cols, order in self.find_ordering_name(field,
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self.query.get_meta(), default_order=asc):
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for col in cols:
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if (table, col) not in processed_pairs:
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elt = '%s.%s' % (qn(table), qn2(col))
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processed_pairs.add((table, col))
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if must_append_to_select and elt not in select_aliases:
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ordering_aliases.append(elt)
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result.append('%s %s' % (elt, order))
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group_by.append((elt, []))
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else:
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elt = qn2(col)
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if col not in self.query.extra_select:
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if must_append_to_select:
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sql = "(%s) AS %s" % (self.query.extra[col][0], elt)
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ordering_aliases.append(sql)
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ordering_params.extend(self.query.extra[col][1])
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result.append('%s %s' % (elt, order))
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else:
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result.append("(%s) %s" % (self.query.extra[col][0], order))
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params.extend(self.query.extra[col][1])
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else:
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result.append('%s %s' % (elt, order))
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group_by.append(self.query.extra[col])
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self.ordering_aliases = ordering_aliases
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self.ordering_params = ordering_params
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return result, params, group_by
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def find_ordering_name(self, name, opts, alias=None, default_order='ASC',
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already_seen=None):
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"""
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Returns the table alias (the name might be ambiguous, the alias will
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not be) and column name for ordering by the given 'name' parameter.
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The 'name' is of the form 'field1__field2__...__fieldN'.
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"""
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name, order = get_order_dir(name, default_order)
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pieces = name.split(LOOKUP_SEP)
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field, targets, alias, joins, path, opts = self._setup_joins(pieces, opts, alias)
|
|
|
|
# If we get to this point and the field is a relation to another model,
|
|
# append the default ordering for that model.
|
|
if field.rel and path and opts.ordering:
|
|
# Firstly, avoid infinite loops.
|
|
if not already_seen:
|
|
already_seen = set()
|
|
join_tuple = tuple(self.query.alias_map[j].table_name for j in joins)
|
|
if join_tuple in already_seen:
|
|
raise FieldError('Infinite loop caused by ordering.')
|
|
already_seen.add(join_tuple)
|
|
|
|
results = []
|
|
for item in opts.ordering:
|
|
results.extend(self.find_ordering_name(item, opts, alias,
|
|
order, already_seen))
|
|
return results
|
|
targets, alias, _ = self.query.trim_joins(targets, joins, path)
|
|
return [(alias, [t.column for t in targets], order)]
|
|
|
|
def _setup_joins(self, pieces, opts, alias):
|
|
"""
|
|
A helper method for get_ordering and get_distinct.
|
|
|
|
Note that get_ordering and get_distinct must produce same target
|
|
columns on same input, as the prefixes of get_ordering and get_distinct
|
|
must match. Executing SQL where this is not true is an error.
|
|
"""
|
|
if not alias:
|
|
alias = self.query.get_initial_alias()
|
|
field, targets, opts, joins, path = self.query.setup_joins(
|
|
pieces, opts, alias)
|
|
alias = joins[-1]
|
|
return field, targets, alias, joins, path, opts
|
|
|
|
def get_from_clause(self):
|
|
"""
|
|
Returns a list of strings that are joined together to go after the
|
|
"FROM" part of the query, as well as a list any extra parameters that
|
|
need to be included. Sub-classes, can override this to create a
|
|
from-clause via a "select".
|
|
|
|
This should only be called after any SQL construction methods that
|
|
might change the tables we need. This means the select columns,
|
|
ordering and distinct must be done first.
|
|
"""
|
|
result = []
|
|
qn = self
|
|
qn2 = self.connection.ops.quote_name
|
|
first = True
|
|
from_params = []
|
|
for alias in self.query.tables:
|
|
if not self.query.alias_refcount[alias]:
|
|
continue
|
|
try:
|
|
name, alias, join_type, lhs, join_cols, _, join_field = self.query.alias_map[alias]
|
|
except KeyError:
|
|
# Extra tables can end up in self.tables, but not in the
|
|
# alias_map if they aren't in a join. That's OK. We skip them.
|
|
continue
|
|
alias_str = '' if alias == name else (' %s' % alias)
|
|
if join_type and not first:
|
|
extra_cond = join_field.get_extra_restriction(
|
|
self.query.where_class, alias, lhs)
|
|
if extra_cond:
|
|
extra_sql, extra_params = self.compile(extra_cond)
|
|
extra_sql = 'AND (%s)' % extra_sql
|
|
from_params.extend(extra_params)
|
|
else:
|
|
extra_sql = ""
|
|
result.append('%s %s%s ON ('
|
|
% (join_type, qn(name), alias_str))
|
|
for index, (lhs_col, rhs_col) in enumerate(join_cols):
|
|
if index != 0:
|
|
result.append(' AND ')
|
|
result.append('%s.%s = %s.%s' %
|
|
(qn(lhs), qn2(lhs_col), qn(alias), qn2(rhs_col)))
|
|
result.append('%s)' % extra_sql)
|
|
else:
|
|
connector = '' if first else ', '
|
|
result.append('%s%s%s' % (connector, qn(name), alias_str))
|
|
first = False
|
|
for t in self.query.extra_tables:
|
|
alias, unused = self.query.table_alias(t)
|
|
# Only add the alias if it's not already present (the table_alias()
|
|
# calls increments the refcount, so an alias refcount of one means
|
|
# this is the only reference.
|
|
if alias not in self.query.alias_map or self.query.alias_refcount[alias] == 1:
|
|
connector = '' if first else ', '
|
|
result.append('%s%s' % (connector, qn(alias)))
|
|
first = False
|
|
return result, from_params
|
|
|
|
def get_grouping(self, having_group_by, ordering_group_by):
|
|
"""
|
|
Returns a tuple representing the SQL elements in the "group by" clause.
|
|
"""
|
|
qn = self
|
|
result, params = [], []
|
|
if self.query.group_by is not None:
|
|
select_cols = self.query.select + self.query.related_select_cols
|
|
# Just the column, not the fields.
|
|
select_cols = [s[0] for s in select_cols]
|
|
if (len(self.query.get_meta().concrete_fields) == len(self.query.select)
|
|
and self.connection.features.allows_group_by_pk):
|
|
self.query.group_by = [
|
|
(self.query.get_meta().db_table, self.query.get_meta().pk.column)
|
|
]
|
|
select_cols = []
|
|
seen = set()
|
|
cols = self.query.group_by + having_group_by + select_cols
|
|
for col in cols:
|
|
col_params = ()
|
|
if isinstance(col, (list, tuple)):
|
|
sql = '%s.%s' % (qn(col[0]), qn(col[1]))
|
|
elif hasattr(col, 'as_sql'):
|
|
self.compile(col)
|
|
else:
|
|
sql = '(%s)' % str(col)
|
|
if sql not in seen:
|
|
result.append(sql)
|
|
params.extend(col_params)
|
|
seen.add(sql)
|
|
|
|
# Still, we need to add all stuff in ordering (except if the backend can
|
|
# group by just by PK).
|
|
if ordering_group_by and not self.connection.features.allows_group_by_pk:
|
|
for order, order_params in ordering_group_by:
|
|
# Even if we have seen the same SQL string, it might have
|
|
# different params, so, we add same SQL in "has params" case.
|
|
if order not in seen or order_params:
|
|
result.append(order)
|
|
params.extend(order_params)
|
|
seen.add(order)
|
|
|
|
# Unconditionally add the extra_select items.
|
|
for extra_select, extra_params in self.query.extra_select.values():
|
|
sql = '(%s)' % str(extra_select)
|
|
result.append(sql)
|
|
params.extend(extra_params)
|
|
|
|
return result, params
|
|
|
|
def fill_related_selections(self, opts=None, root_alias=None, cur_depth=1,
|
|
requested=None, restricted=None):
|
|
"""
|
|
Fill in the information needed for a select_related query. The current
|
|
depth is measured as the number of connections away from the root model
|
|
(for example, cur_depth=1 means we are looking at models with direct
|
|
connections to the root model).
|
|
"""
|
|
if not restricted and self.query.max_depth and cur_depth > self.query.max_depth:
|
|
# We've recursed far enough; bail out.
|
|
return
|
|
|
|
if not opts:
|
|
opts = self.query.get_meta()
|
|
root_alias = self.query.get_initial_alias()
|
|
self.query.related_select_cols = []
|
|
only_load = self.query.get_loaded_field_names()
|
|
|
|
# Setup for the case when only particular related fields should be
|
|
# included in the related selection.
|
|
if requested is None:
|
|
if isinstance(self.query.select_related, dict):
|
|
requested = self.query.select_related
|
|
restricted = True
|
|
else:
|
|
restricted = False
|
|
|
|
for f, model in opts.get_fields_with_model():
|
|
# The get_fields_with_model() returns None for fields that live
|
|
# in the field's local model. So, for those fields we want to use
|
|
# the f.model - that is the field's local model.
|
|
field_model = model or f.model
|
|
if not select_related_descend(f, restricted, requested,
|
|
only_load.get(field_model)):
|
|
continue
|
|
_, _, _, joins, _ = self.query.setup_joins(
|
|
[f.name], opts, root_alias)
|
|
alias = joins[-1]
|
|
columns, _ = self.get_default_columns(start_alias=alias,
|
|
opts=f.rel.to._meta, as_pairs=True)
|
|
self.query.related_select_cols.extend(
|
|
SelectInfo((col[0], col[1].column), col[1]) for col in columns)
|
|
if restricted:
|
|
next = requested.get(f.name, {})
|
|
else:
|
|
next = False
|
|
self.fill_related_selections(f.rel.to._meta, alias, cur_depth + 1,
|
|
next, restricted)
|
|
|
|
if restricted:
|
|
related_fields = [
|
|
(o.field, o.model)
|
|
for o in opts.get_all_related_objects()
|
|
if o.field.unique
|
|
]
|
|
for f, model in related_fields:
|
|
if not select_related_descend(f, restricted, requested,
|
|
only_load.get(model), reverse=True):
|
|
continue
|
|
|
|
_, _, _, joins, _ = self.query.setup_joins(
|
|
[f.related_query_name()], opts, root_alias)
|
|
alias = joins[-1]
|
|
from_parent = (opts.model if issubclass(model, opts.model)
|
|
else None)
|
|
columns, _ = self.get_default_columns(start_alias=alias,
|
|
opts=model._meta, as_pairs=True, from_parent=from_parent)
|
|
self.query.related_select_cols.extend(
|
|
SelectInfo((col[0], col[1].column), col[1]) for col in columns)
|
|
next = requested.get(f.related_query_name(), {})
|
|
self.fill_related_selections(model._meta, alias, cur_depth + 1,
|
|
next, restricted)
|
|
|
|
def deferred_to_columns(self):
|
|
"""
|
|
Converts the self.deferred_loading data structure to mapping of table
|
|
names to sets of column names which are to be loaded. Returns the
|
|
dictionary.
|
|
"""
|
|
columns = {}
|
|
self.query.deferred_to_data(columns, self.query.deferred_to_columns_cb)
|
|
return columns
|
|
|
|
def results_iter(self):
|
|
"""
|
|
Returns an iterator over the results from executing this query.
|
|
"""
|
|
resolve_columns = hasattr(self, 'resolve_columns')
|
|
fields = None
|
|
has_aggregate_select = bool(self.query.aggregate_select)
|
|
for rows in self.execute_sql(MULTI):
|
|
for row in rows:
|
|
if has_aggregate_select:
|
|
loaded_fields = self.query.get_loaded_field_names().get(self.query.model, set()) or self.query.select
|
|
aggregate_start = len(self.query.extra_select) + len(loaded_fields)
|
|
aggregate_end = aggregate_start + len(self.query.aggregate_select)
|
|
if resolve_columns:
|
|
if fields is None:
|
|
# We only set this up here because
|
|
# related_select_cols isn't populated until
|
|
# execute_sql() has been called.
|
|
|
|
# We also include types of fields of related models that
|
|
# will be included via select_related() for the benefit
|
|
# of MySQL/MySQLdb when boolean fields are involved
|
|
# (#15040).
|
|
|
|
# This code duplicates the logic for the order of fields
|
|
# found in get_columns(). It would be nice to clean this up.
|
|
if self.query.select:
|
|
fields = [f.field for f in self.query.select]
|
|
elif self.query.default_cols:
|
|
fields = self.query.get_meta().concrete_fields
|
|
else:
|
|
fields = []
|
|
fields = fields + [f.field for f in self.query.related_select_cols]
|
|
|
|
# If the field was deferred, exclude it from being passed
|
|
# into `resolve_columns` because it wasn't selected.
|
|
only_load = self.deferred_to_columns()
|
|
if only_load:
|
|
fields = [f for f in fields if f.model._meta.db_table not in only_load or
|
|
f.column in only_load[f.model._meta.db_table]]
|
|
if has_aggregate_select:
|
|
# pad None in to fields for aggregates
|
|
fields = fields[:aggregate_start] + [
|
|
None for x in range(0, aggregate_end - aggregate_start)
|
|
] + fields[aggregate_start:]
|
|
row = self.resolve_columns(row, fields)
|
|
|
|
if has_aggregate_select:
|
|
row = tuple(row[:aggregate_start]) + tuple(
|
|
self.query.resolve_aggregate(value, aggregate, self.connection)
|
|
for (alias, aggregate), value
|
|
in zip(self.query.aggregate_select.items(), row[aggregate_start:aggregate_end])
|
|
) + tuple(row[aggregate_end:])
|
|
|
|
yield row
|
|
|
|
def has_results(self):
|
|
"""
|
|
Backends (e.g. NoSQL) can override this in order to use optimized
|
|
versions of "query has any results."
|
|
"""
|
|
# This is always executed on a query clone, so we can modify self.query
|
|
self.query.add_extra({'a': 1}, None, None, None, None, None)
|
|
self.query.set_extra_mask(['a'])
|
|
return bool(self.execute_sql(SINGLE))
|
|
|
|
def execute_sql(self, result_type=MULTI):
|
|
"""
|
|
Run the query against the database and returns the result(s). The
|
|
return value is a single data item if result_type is SINGLE, or an
|
|
iterator over the results if the result_type is MULTI.
|
|
|
|
result_type is either MULTI (use fetchmany() to retrieve all rows),
|
|
SINGLE (only retrieve a single row), or None. In this last case, the
|
|
cursor is returned if any query is executed, since it's used by
|
|
subclasses such as InsertQuery). It's possible, however, that no query
|
|
is needed, as the filters describe an empty set. In that case, None is
|
|
returned, to avoid any unnecessary database interaction.
|
|
"""
|
|
try:
|
|
sql, params = self.as_sql()
|
|
if not sql:
|
|
raise EmptyResultSet
|
|
except EmptyResultSet:
|
|
if result_type == MULTI:
|
|
return iter([])
|
|
else:
|
|
return
|
|
|
|
cursor = self.connection.cursor()
|
|
cursor.execute(sql, params)
|
|
|
|
if not result_type:
|
|
return cursor
|
|
if result_type == SINGLE:
|
|
if self.ordering_aliases:
|
|
return cursor.fetchone()[:-len(self.ordering_aliases)]
|
|
return cursor.fetchone()
|
|
|
|
# The MULTI case.
|
|
if self.ordering_aliases:
|
|
result = order_modified_iter(cursor, len(self.ordering_aliases),
|
|
self.connection.features.empty_fetchmany_value)
|
|
else:
|
|
result = iter((lambda: cursor.fetchmany(GET_ITERATOR_CHUNK_SIZE)),
|
|
self.connection.features.empty_fetchmany_value)
|
|
if not self.connection.features.can_use_chunked_reads:
|
|
# If we are using non-chunked reads, we return the same data
|
|
# structure as normally, but ensure it is all read into memory
|
|
# before going any further.
|
|
return list(result)
|
|
return result
|
|
|
|
def as_subquery_condition(self, alias, columns, qn):
|
|
inner_qn = self
|
|
qn2 = self.connection.ops.quote_name
|
|
if len(columns) == 1:
|
|
sql, params = self.as_sql()
|
|
return '%s.%s IN (%s)' % (qn(alias), qn2(columns[0]), sql), params
|
|
|
|
for index, select_col in enumerate(self.query.select):
|
|
lhs = '%s.%s' % (inner_qn(select_col.col[0]), qn2(select_col.col[1]))
|
|
rhs = '%s.%s' % (qn(alias), qn2(columns[index]))
|
|
self.query.where.add(
|
|
QueryWrapper('%s = %s' % (lhs, rhs), []), 'AND')
|
|
|
|
sql, params = self.as_sql()
|
|
return 'EXISTS (%s)' % sql, params
|
|
|
|
|
|
class SQLInsertCompiler(SQLCompiler):
|
|
|
|
def __init__(self, *args, **kwargs):
|
|
self.return_id = False
|
|
super(SQLInsertCompiler, self).__init__(*args, **kwargs)
|
|
|
|
def placeholder(self, field, val):
|
|
if field is None:
|
|
# A field value of None means the value is raw.
|
|
return val
|
|
elif hasattr(field, 'get_placeholder'):
|
|
# Some fields (e.g. geo fields) need special munging before
|
|
# they can be inserted.
|
|
return field.get_placeholder(val, self.connection)
|
|
else:
|
|
# Return the common case for the placeholder
|
|
return '%s'
|
|
|
|
def as_sql(self):
|
|
# We don't need quote_name_unless_alias() here, since these are all
|
|
# going to be column names (so we can avoid the extra overhead).
|
|
qn = self.connection.ops.quote_name
|
|
opts = self.query.get_meta()
|
|
result = ['INSERT INTO %s' % qn(opts.db_table)]
|
|
|
|
has_fields = bool(self.query.fields)
|
|
fields = self.query.fields if has_fields else [opts.pk]
|
|
result.append('(%s)' % ', '.join(qn(f.column) for f in fields))
|
|
|
|
if has_fields:
|
|
params = values = [
|
|
[
|
|
f.get_db_prep_save(getattr(obj, f.attname) if self.query.raw else f.pre_save(obj, True), connection=self.connection)
|
|
for f in fields
|
|
]
|
|
for obj in self.query.objs
|
|
]
|
|
else:
|
|
values = [[self.connection.ops.pk_default_value()] for obj in self.query.objs]
|
|
params = [[]]
|
|
fields = [None]
|
|
can_bulk = (not any(hasattr(field, "get_placeholder") for field in fields) and
|
|
not self.return_id and self.connection.features.has_bulk_insert)
|
|
|
|
if can_bulk:
|
|
placeholders = [["%s"] * len(fields)]
|
|
else:
|
|
placeholders = [
|
|
[self.placeholder(field, v) for field, v in zip(fields, val)]
|
|
for val in values
|
|
]
|
|
# Oracle Spatial needs to remove some values due to #10888
|
|
params = self.connection.ops.modify_insert_params(placeholders, params)
|
|
if self.return_id and self.connection.features.can_return_id_from_insert:
|
|
params = params[0]
|
|
col = "%s.%s" % (qn(opts.db_table), qn(opts.pk.column))
|
|
result.append("VALUES (%s)" % ", ".join(placeholders[0]))
|
|
r_fmt, r_params = self.connection.ops.return_insert_id()
|
|
# Skip empty r_fmt to allow subclasses to customize behaviour for
|
|
# 3rd party backends. Refs #19096.
|
|
if r_fmt:
|
|
result.append(r_fmt % col)
|
|
params += r_params
|
|
return [(" ".join(result), tuple(params))]
|
|
if can_bulk:
|
|
result.append(self.connection.ops.bulk_insert_sql(fields, len(values)))
|
|
return [(" ".join(result), tuple(v for val in values for v in val))]
|
|
else:
|
|
return [
|
|
(" ".join(result + ["VALUES (%s)" % ", ".join(p)]), vals)
|
|
for p, vals in zip(placeholders, params)
|
|
]
|
|
|
|
def execute_sql(self, return_id=False):
|
|
assert not (return_id and len(self.query.objs) != 1)
|
|
self.return_id = return_id
|
|
cursor = self.connection.cursor()
|
|
for sql, params in self.as_sql():
|
|
cursor.execute(sql, params)
|
|
if not (return_id and cursor):
|
|
return
|
|
if self.connection.features.can_return_id_from_insert:
|
|
return self.connection.ops.fetch_returned_insert_id(cursor)
|
|
return self.connection.ops.last_insert_id(cursor,
|
|
self.query.get_meta().db_table, self.query.get_meta().pk.column)
|
|
|
|
|
|
class SQLDeleteCompiler(SQLCompiler):
|
|
def as_sql(self):
|
|
"""
|
|
Creates the SQL for this query. Returns the SQL string and list of
|
|
parameters.
|
|
"""
|
|
assert len(self.query.tables) == 1, \
|
|
"Can only delete from one table at a time."
|
|
qn = self
|
|
result = ['DELETE FROM %s' % qn(self.query.tables[0])]
|
|
where, params = self.compile(self.query.where)
|
|
if where:
|
|
result.append('WHERE %s' % where)
|
|
return ' '.join(result), tuple(params)
|
|
|
|
|
|
class SQLUpdateCompiler(SQLCompiler):
|
|
def as_sql(self):
|
|
"""
|
|
Creates the SQL for this query. Returns the SQL string and list of
|
|
parameters.
|
|
"""
|
|
self.pre_sql_setup()
|
|
if not self.query.values:
|
|
return '', ()
|
|
table = self.query.tables[0]
|
|
qn = self
|
|
result = ['UPDATE %s' % qn(table)]
|
|
result.append('SET')
|
|
values, update_params = [], []
|
|
for field, model, val in self.query.values:
|
|
if hasattr(val, 'prepare_database_save'):
|
|
val = val.prepare_database_save(field)
|
|
else:
|
|
val = field.get_db_prep_save(val, connection=self.connection)
|
|
|
|
# Getting the placeholder for the field.
|
|
if hasattr(field, 'get_placeholder'):
|
|
placeholder = field.get_placeholder(val, self.connection)
|
|
else:
|
|
placeholder = '%s'
|
|
|
|
if hasattr(val, 'evaluate'):
|
|
val = SQLEvaluator(val, self.query, allow_joins=False)
|
|
name = field.column
|
|
if hasattr(val, 'as_sql'):
|
|
sql, params = self.compile(val)
|
|
values.append('%s = %s' % (qn(name), sql))
|
|
update_params.extend(params)
|
|
elif val is not None:
|
|
values.append('%s = %s' % (qn(name), placeholder))
|
|
update_params.append(val)
|
|
else:
|
|
values.append('%s = NULL' % qn(name))
|
|
if not values:
|
|
return '', ()
|
|
result.append(', '.join(values))
|
|
where, params = self.compile(self.query.where)
|
|
if where:
|
|
result.append('WHERE %s' % where)
|
|
return ' '.join(result), tuple(update_params + params)
|
|
|
|
def execute_sql(self, result_type):
|
|
"""
|
|
Execute the specified update. Returns the number of rows affected by
|
|
the primary update query. The "primary update query" is the first
|
|
non-empty query that is executed. Row counts for any subsequent,
|
|
related queries are not available.
|
|
"""
|
|
cursor = super(SQLUpdateCompiler, self).execute_sql(result_type)
|
|
rows = cursor.rowcount if cursor else 0
|
|
is_empty = cursor is None
|
|
del cursor
|
|
for query in self.query.get_related_updates():
|
|
aux_rows = query.get_compiler(self.using).execute_sql(result_type)
|
|
if is_empty:
|
|
rows = aux_rows
|
|
is_empty = False
|
|
return rows
|
|
|
|
def pre_sql_setup(self):
|
|
"""
|
|
If the update depends on results from other tables, we need to do some
|
|
munging of the "where" conditions to match the format required for
|
|
(portable) SQL updates. That is done here.
|
|
|
|
Further, if we are going to be running multiple updates, we pull out
|
|
the id values to update at this point so that they don't change as a
|
|
result of the progressive updates.
|
|
"""
|
|
self.query.select_related = False
|
|
self.query.clear_ordering(True)
|
|
super(SQLUpdateCompiler, self).pre_sql_setup()
|
|
count = self.query.count_active_tables()
|
|
if not self.query.related_updates and count == 1:
|
|
return
|
|
|
|
# We need to use a sub-select in the where clause to filter on things
|
|
# from other tables.
|
|
query = self.query.clone(klass=Query)
|
|
query._extra = {}
|
|
query.select = []
|
|
query.add_fields([query.get_meta().pk.name])
|
|
# Recheck the count - it is possible that fiddling with the select
|
|
# fields above removes tables from the query. Refs #18304.
|
|
count = query.count_active_tables()
|
|
if not self.query.related_updates and count == 1:
|
|
return
|
|
|
|
must_pre_select = count > 1 and not self.connection.features.update_can_self_select
|
|
|
|
# Now we adjust the current query: reset the where clause and get rid
|
|
# of all the tables we don't need (since they're in the sub-select).
|
|
self.query.where = self.query.where_class()
|
|
if self.query.related_updates or must_pre_select:
|
|
# Either we're using the idents in multiple update queries (so
|
|
# don't want them to change), or the db backend doesn't support
|
|
# selecting from the updating table (e.g. MySQL).
|
|
idents = []
|
|
for rows in query.get_compiler(self.using).execute_sql(MULTI):
|
|
idents.extend(r[0] for r in rows)
|
|
self.query.add_filter(('pk__in', idents))
|
|
self.query.related_ids = idents
|
|
else:
|
|
# The fast path. Filters and updates in one query.
|
|
self.query.add_filter(('pk__in', query))
|
|
for alias in self.query.tables[1:]:
|
|
self.query.alias_refcount[alias] = 0
|
|
|
|
|
|
class SQLAggregateCompiler(SQLCompiler):
|
|
def as_sql(self, qn=None):
|
|
"""
|
|
Creates the SQL for this query. Returns the SQL string and list of
|
|
parameters.
|
|
"""
|
|
if qn is None:
|
|
qn = self
|
|
|
|
sql, params = [], []
|
|
for aggregate in self.query.aggregate_select.values():
|
|
agg_sql, agg_params = self.compile(aggregate)
|
|
sql.append(agg_sql)
|
|
params.extend(agg_params)
|
|
sql = ', '.join(sql)
|
|
params = tuple(params)
|
|
|
|
sql = 'SELECT %s FROM (%s) subquery' % (sql, self.query.subquery)
|
|
params = params + self.query.sub_params
|
|
return sql, params
|
|
|
|
|
|
class SQLDateCompiler(SQLCompiler):
|
|
def results_iter(self):
|
|
"""
|
|
Returns an iterator over the results from executing this query.
|
|
"""
|
|
resolve_columns = hasattr(self, 'resolve_columns')
|
|
if resolve_columns:
|
|
from django.db.models.fields import DateField
|
|
fields = [DateField()]
|
|
else:
|
|
from django.db.backends.utils import typecast_date
|
|
needs_string_cast = self.connection.features.needs_datetime_string_cast
|
|
|
|
offset = len(self.query.extra_select)
|
|
for rows in self.execute_sql(MULTI):
|
|
for row in rows:
|
|
date = row[offset]
|
|
if resolve_columns:
|
|
date = self.resolve_columns(row, fields)[offset]
|
|
elif needs_string_cast:
|
|
date = typecast_date(str(date))
|
|
if isinstance(date, datetime.datetime):
|
|
date = date.date()
|
|
yield date
|
|
|
|
|
|
class SQLDateTimeCompiler(SQLCompiler):
|
|
def results_iter(self):
|
|
"""
|
|
Returns an iterator over the results from executing this query.
|
|
"""
|
|
resolve_columns = hasattr(self, 'resolve_columns')
|
|
if resolve_columns:
|
|
from django.db.models.fields import DateTimeField
|
|
fields = [DateTimeField()]
|
|
else:
|
|
from django.db.backends.utils import typecast_timestamp
|
|
needs_string_cast = self.connection.features.needs_datetime_string_cast
|
|
|
|
offset = len(self.query.extra_select)
|
|
for rows in self.execute_sql(MULTI):
|
|
for row in rows:
|
|
datetime = row[offset]
|
|
if resolve_columns:
|
|
datetime = self.resolve_columns(row, fields)[offset]
|
|
elif needs_string_cast:
|
|
datetime = typecast_timestamp(str(datetime))
|
|
# Datetimes are artifically returned in UTC on databases that
|
|
# don't support time zone. Restore the zone used in the query.
|
|
if settings.USE_TZ:
|
|
if datetime is None:
|
|
raise ValueError("Database returned an invalid value "
|
|
"in QuerySet.datetimes(). Are time zone "
|
|
"definitions for your database and pytz installed?")
|
|
datetime = datetime.replace(tzinfo=None)
|
|
datetime = timezone.make_aware(datetime, self.query.tzinfo)
|
|
yield datetime
|
|
|
|
|
|
def order_modified_iter(cursor, trim, sentinel):
|
|
"""
|
|
Yields blocks of rows from a cursor. We use this iterator in the special
|
|
case when extra output columns have been added to support ordering
|
|
requirements. We must trim those extra columns before anything else can use
|
|
the results, since they're only needed to make the SQL valid.
|
|
"""
|
|
for rows in iter((lambda: cursor.fetchmany(GET_ITERATOR_CHUNK_SIZE)),
|
|
sentinel):
|
|
yield [r[:-trim] for r in rows]
|