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Fixed #7270 -- Added the ability to follow reverse OneToOneFields in select_related(). Thanks to George Vilches, Ben Davis, and Alex Gaynor for their work on various stages of this patch.

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git-svn-id: http://code.djangoproject.com/svn/django/trunk@12307 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
Russell Keith-Magee 2010-01-27 13:30:29 +00:00
parent 8e8d4b5888
commit 58cd220f51
9 changed files with 306 additions and 14 deletions
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68
django/db/models/sql/compiler.py
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@ -520,7 +520,7 @@ class SQLCompiler(object):
# Setup for the case when only particular related fields should be
# included in the related selection.
if requested is None and restricted is not False:
if requested is None:
if isinstance(self.query.select_related, dict):
requested = self.query.select_related
restricted = True
@ -600,6 +600,72 @@ class SQLCompiler(object):
self.fill_related_selections(f.rel.to._meta, alias, cur_depth + 1,
used, next, restricted, new_nullable, dupe_set, avoid)
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, reverse=True):
continue
# The "avoid" set is aliases we want to avoid just for this
# particular branch of the recursion. They aren't permanently
# forbidden from reuse in the related selection tables (which is
# what "used" specifies).
avoid = avoid_set.copy()
dupe_set = orig_dupe_set.copy()
table = model._meta.db_table
int_opts = opts
alias = root_alias
alias_chain = []
chain = opts.get_base_chain(f.rel.to)
if chain is not None:
for int_model in chain:
# Proxy model have elements in base chain
# with no parents, assign the new options
# object and skip to the next base in that
# case
if not int_opts.parents[int_model]:
int_opts = int_model._meta
continue
lhs_col = int_opts.parents[int_model].column
dedupe = lhs_col in opts.duplicate_targets
if dedupe:
avoid.update(self.query.dupe_avoidance.get(id(opts), lhs_col),
())
dupe_set.add((opts, lhs_col))
int_opts = int_model._meta
alias = self.query.join(
(alias, int_opts.db_table, lhs_col, int_opts.pk.column),
exclusions=used, promote=True, reuse=used
)
alias_chain.append(alias)
for dupe_opts, dupe_col in dupe_set:
self.query.update_dupe_avoidance(dupe_opts, dupe_col, alias)
dedupe = f.column in opts.duplicate_targets
if dupe_set or dedupe:
avoid.update(self.query.dupe_avoidance.get((id(opts), f.column), ()))
if dedupe:
dupe_set.add((opts, f.column))
alias = self.query.join(
(alias, table, f.rel.get_related_field().column, f.column),
exclusions=used.union(avoid),
promote=True
)
used.add(alias)
columns, aliases = self.get_default_columns(start_alias=alias,
opts=model._meta, as_pairs=True)
self.query.related_select_cols.extend(columns)
self.query.related_select_fields.extend(model._meta.fields)
next = requested.get(f.related_query_name(), {})
new_nullable = f.null or None
self.fill_related_selections(model._meta, table, cur_depth+1,
used, next, restricted, new_nullable)
def deferred_to_columns(self):
"""
Converts the self.deferred_loading data structure to mapping of table