def fill_related_selections(self, opts=None, root_alias=None, cur_depth=1,
            used=None, requested=None, restricted=None, nullable=None,
            dupe_set=None, avoid_set=None):
        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 = []
            self.query.related_select_fields = []
        if not used:
            used = set()
        if dupe_set is None:
            dupe_set = set()
        if avoid_set is None:
            avoid_set = set()
        orig_dupe_set = dupe_set

        # 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():
            if not select_related_descend(f, restricted, requested):
                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 = f.rel.to._meta.db_table
            promote = nullable or f.null
            if model:
                int_opts = opts
                alias = root_alias
                alias_chain = []
                for int_model in opts.get_base_chain(model):
                    # 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=promote)
                    alias_chain.append(alias)
                    for (dupe_opts, dupe_col) in dupe_set:
                        self.query.update_dupe_avoidance(dupe_opts, dupe_col, alias)
                if self.query.alias_map[root_alias][JOIN_TYPE] == self.query.LOUTER:
                    self.query.promote_alias_chain(alias_chain, True)
            else:
                alias = root_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.column,
                    f.rel.get_related_field().column),
                    exclusions=used.union(avoid), promote=promote)
            used.add(alias)
            columns, aliases = self.get_default_columns(start_alias=alias,
                    opts=f.rel.to._meta, as_pairs=True)
            self.query.related_select_cols.extend(columns)
            if self.query.alias_map[alias][JOIN_TYPE] == self.query.LOUTER:
                self.query.promote_alias_chain(aliases, True)
            self.query.related_select_fields.extend(f.rel.to._meta.fields)
            if restricted:
                next = requested.get(f.name, {})
            else:
                next = False
            new_nullable = f.null or promote
            for dupe_opts, dupe_col in dupe_set:
                self.query.update_dupe_avoidance(dupe_opts, dupe_col, alias)
            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, local_only=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)
Fill in the information needed for a select_related query. The current
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.2/django/db/models/sql/compiler.py/SQLCompiler.fill_related_selections