django1/django/db/models/sql/expressions.py

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from django.core.exceptions import FieldError
from django.db.models.constants import LOOKUP_SEP
from django.db.models.fields import FieldDoesNotExist
class SQLEvaluator(object):
def __init__(self, expression, query, allow_joins=True, reuse=None):
self.expression = expression
self.opts = query.get_meta()
self.cols = []
self.contains_aggregate = False
self.reuse = reuse
self.expression.prepare(self, query, allow_joins)
def prepare(self):
return self
def as_sql(self, qn, connection):
return self.expression.evaluate(self, qn, connection)
def relabel_aliases(self, change_map):
new_cols = []
for node, col in self.cols:
if hasattr(col, "relabel_aliases"):
col.relabel_aliases(change_map)
new_cols.append((node, col))
else:
new_cols.append((node,
(change_map.get(col[0], col[0]), col[1])))
self.cols = new_cols
#####################################################
# Vistor methods for initial expression preparation #
#####################################################
def prepare_node(self, node, query, allow_joins):
for child in node.children:
if hasattr(child, 'prepare'):
child.prepare(self, query, allow_joins)
def prepare_leaf(self, node, query, allow_joins):
if not allow_joins and LOOKUP_SEP in node.name:
raise FieldError("Joined field references are not permitted in this query")
field_list = node.name.split(LOOKUP_SEP)
if (len(field_list) == 1 and
node.name in query.aggregate_select.keys()):
self.contains_aggregate = True
self.cols.append((node, query.aggregate_select[node.name]))
else:
try:
field, source, opts, join_list, path = query.setup_joins(
field_list, query.get_meta(),
query.get_initial_alias(), self.reuse)
col, _, join_list = query.trim_joins(source, join_list, path)
if self.reuse is not None:
self.reuse.update(join_list)
self.cols.append((node, (join_list[-1], col)))
except FieldDoesNotExist:
raise FieldError("Cannot resolve keyword %r into field. "
"Choices are: %s" % (self.name,
[f.name for f in self.opts.fields]))
##################################################
# Vistor methods for final expression evaluation #
##################################################
def evaluate_node(self, node, qn, connection):
expressions = []
expression_params = []
for child in node.children:
if hasattr(child, 'evaluate'):
sql, params = child.evaluate(self, qn, connection)
else:
sql, params = '%s', (child,)
if len(getattr(child, 'children', [])) > 1:
format = '(%s)'
else:
format = '%s'
if sql:
expressions.append(format % sql)
expression_params.extend(params)
return connection.ops.combine_expression(node.connector, expressions), expression_params
def evaluate_leaf(self, node, qn, connection):
col = None
for n, c in self.cols:
if n is node:
col = c
break
if col is None:
raise ValueError("Given node not found")
if hasattr(col, 'as_sql'):
Fixed #17260 -- Added time zone aware aggregation and lookups. Thanks Carl Meyer for the review. Squashed commit of the following: commit 4f290bdb60b7d8534abf4ca901bd0844612dcbda Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Wed Feb 13 21:21:30 2013 +0100 Used '0:00' instead of 'UTC' which doesn't always exist in Oracle. Thanks Ian Kelly for the suggestion. commit 01b6366f3ce67d57a58ca8f25e5be77911748638 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Wed Feb 13 13:38:43 2013 +0100 Made tzname a parameter of datetime_extract/trunc_sql. This is required to work around a bug in Oracle. commit 924a144ef8a80ba4daeeafbe9efaa826566e9d02 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Wed Feb 13 14:47:44 2013 +0100 Added support for parameters in SELECT clauses. commit b4351d2890cd1090d3ff2d203fe148937324c935 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Mon Feb 11 22:30:22 2013 +0100 Documented backwards incompatibilities in the two previous commits. commit 91ef84713c81bd455f559dacf790e586d08cacb9 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Mon Feb 11 09:42:31 2013 +0100 Used QuerySet.datetimes for the admin's date_hierarchy. commit 0d0de288a5210fa106cd4350961eb2006535cc5c Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Mon Feb 11 09:29:38 2013 +0100 Used QuerySet.datetimes in date-based generic views. commit 9c0859ff7c0b00734afe7fc15609d43d83215072 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Sun Feb 10 21:43:25 2013 +0100 Implemented QuerySet.datetimes on Oracle. commit 68ab511a4ffbd2b811bf5da174d47e4dd90f28fc Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Sun Feb 10 21:43:14 2013 +0100 Implemented QuerySet.datetimes on MySQL. commit 22d52681d347a8cdf568dc31ed032cbc61d049ef Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Sun Feb 10 21:42:29 2013 +0100 Implemented QuerySet.datetimes on SQLite. commit f6800fd04c93722b45f9236976389e0b2fe436f5 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Sun Feb 10 21:43:03 2013 +0100 Implemented QuerySet.datetimes on PostgreSQL. commit 0c829c23f4cf4d6804cadcc93032dd4c26b8c65e Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Sun Feb 10 21:41:08 2013 +0100 Added datetime-handling infrastructure in the ORM layers. commit 104d82a7778cf3f0f5d03dfa53709c26df45daad Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Mon Feb 11 10:05:55 2013 +0100 Updated null_queries tests to avoid clashing with the __second lookup. commit c01bbb32358201b3ac8cb4291ef87b7612a2b8e6 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Sun Feb 10 23:07:41 2013 +0100 Updated tests of .dates(). Replaced .dates() by .datetimes() for DateTimeFields. Replaced dates with datetimes in the expected output for DateFields. commit 50fb7a52462fecf0127b38e7f3df322aeb287c43 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Sun Feb 10 21:40:09 2013 +0100 Updated and added tests for QuerySet.datetimes. commit a8451a5004c437190e264667b1e6fb8acc3c1eeb Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Sun Feb 10 22:34:46 2013 +0100 Documented the new time lookups and updated the date lookups. commit 29413eab2bd1d5e004598900c0dadc0521bbf4d3 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Sun Feb 10 16:15:49 2013 +0100 Documented QuerySet.datetimes and updated QuerySet.dates.
2013-02-10 23:15:49 +08:00
return col.as_sql(qn, connection)
else:
Fixed #17260 -- Added time zone aware aggregation and lookups. Thanks Carl Meyer for the review. Squashed commit of the following: commit 4f290bdb60b7d8534abf4ca901bd0844612dcbda Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Wed Feb 13 21:21:30 2013 +0100 Used '0:00' instead of 'UTC' which doesn't always exist in Oracle. Thanks Ian Kelly for the suggestion. commit 01b6366f3ce67d57a58ca8f25e5be77911748638 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Wed Feb 13 13:38:43 2013 +0100 Made tzname a parameter of datetime_extract/trunc_sql. This is required to work around a bug in Oracle. commit 924a144ef8a80ba4daeeafbe9efaa826566e9d02 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Wed Feb 13 14:47:44 2013 +0100 Added support for parameters in SELECT clauses. commit b4351d2890cd1090d3ff2d203fe148937324c935 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Mon Feb 11 22:30:22 2013 +0100 Documented backwards incompatibilities in the two previous commits. commit 91ef84713c81bd455f559dacf790e586d08cacb9 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Mon Feb 11 09:42:31 2013 +0100 Used QuerySet.datetimes for the admin's date_hierarchy. commit 0d0de288a5210fa106cd4350961eb2006535cc5c Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Mon Feb 11 09:29:38 2013 +0100 Used QuerySet.datetimes in date-based generic views. commit 9c0859ff7c0b00734afe7fc15609d43d83215072 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Sun Feb 10 21:43:25 2013 +0100 Implemented QuerySet.datetimes on Oracle. commit 68ab511a4ffbd2b811bf5da174d47e4dd90f28fc Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Sun Feb 10 21:43:14 2013 +0100 Implemented QuerySet.datetimes on MySQL. commit 22d52681d347a8cdf568dc31ed032cbc61d049ef Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Sun Feb 10 21:42:29 2013 +0100 Implemented QuerySet.datetimes on SQLite. commit f6800fd04c93722b45f9236976389e0b2fe436f5 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Sun Feb 10 21:43:03 2013 +0100 Implemented QuerySet.datetimes on PostgreSQL. commit 0c829c23f4cf4d6804cadcc93032dd4c26b8c65e Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Sun Feb 10 21:41:08 2013 +0100 Added datetime-handling infrastructure in the ORM layers. commit 104d82a7778cf3f0f5d03dfa53709c26df45daad Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Mon Feb 11 10:05:55 2013 +0100 Updated null_queries tests to avoid clashing with the __second lookup. commit c01bbb32358201b3ac8cb4291ef87b7612a2b8e6 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Sun Feb 10 23:07:41 2013 +0100 Updated tests of .dates(). Replaced .dates() by .datetimes() for DateTimeFields. Replaced dates with datetimes in the expected output for DateFields. commit 50fb7a52462fecf0127b38e7f3df322aeb287c43 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Sun Feb 10 21:40:09 2013 +0100 Updated and added tests for QuerySet.datetimes. commit a8451a5004c437190e264667b1e6fb8acc3c1eeb Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Sun Feb 10 22:34:46 2013 +0100 Documented the new time lookups and updated the date lookups. commit 29413eab2bd1d5e004598900c0dadc0521bbf4d3 Author: Aymeric Augustin <aymeric.augustin@m4x.org> Date: Sun Feb 10 16:15:49 2013 +0100 Documented QuerySet.datetimes and updated QuerySet.dates.
2013-02-10 23:15:49 +08:00
return '%s.%s' % (qn(col[0]), qn(col[1])), []
def evaluate_date_modifier_node(self, node, qn, connection):
timedelta = node.children.pop()
sql, params = self.evaluate_node(node, qn, connection)
if timedelta.days == 0 and timedelta.seconds == 0 and \
timedelta.microseconds == 0:
return sql, params
return connection.ops.date_interval_sql(sql, node.connector, timedelta), params