start-pack

myenv/lib/python3.12/site-packages/django/db/models/sql/__init__.py

@@ -0,0 +1,6 @@
+from django.db.models.sql.query import *  # NOQA
+from django.db.models.sql.query import Query
+from django.db.models.sql.subqueries import *  # NOQA
+from django.db.models.sql.where import AND, OR, XOR
+
+__all__ = ["Query", "AND", "OR", "XOR"]

myenv/lib/python3.12/site-packages/django/db/models/sql/constants.py

@@ -0,0 +1,26 @@
+"""
+Constants specific to the SQL storage portion of the ORM.
+"""
+
+# 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
+
+# Namedtuples for sql.* internal use.
+
+# How many results to expect from a cursor.execute call
+MULTI = "multi"
+SINGLE = "single"
+NO_RESULTS = "no results"
+# Rather than returning results, returns:
+CURSOR = "cursor"
+ROW_COUNT = "row count"
+
+ORDER_DIR = {
+    "ASC": ("ASC", "DESC"),
+    "DESC": ("DESC", "ASC"),
+}
+
+# SQL join types.
+INNER = "INNER JOIN"
+LOUTER = "LEFT OUTER JOIN"

myenv/lib/python3.12/site-packages/django/db/models/sql/datastructures.py

@@ -0,0 +1,238 @@
+"""
+Useful auxiliary data structures for query construction. Not useful outside
+the SQL domain.
+"""
+
+import warnings
+
+from django.core.exceptions import FullResultSet
+from django.db.models.sql.constants import INNER, LOUTER
+from django.utils.deprecation import RemovedInDjango60Warning
+
+
+class MultiJoin(Exception):
+    """
+    Used by join construction code to indicate the point at which a
+    multi-valued join was attempted (if the caller wants to treat that
+    exceptionally).
+    """
+
+    def __init__(self, names_pos, path_with_names):
+        self.level = names_pos
+        # The path travelled, this includes the path to the multijoin.
+        self.names_with_path = path_with_names
+
+
+class Empty:
+    pass
+
+
+class Join:
+    """
+    Used by sql.Query and sql.SQLCompiler to generate JOIN clauses into the
+    FROM entry. For example, the SQL generated could be
+        LEFT OUTER JOIN "sometable" T1
+        ON ("othertable"."sometable_id" = "sometable"."id")
+
+    This class is primarily used in Query.alias_map. All entries in alias_map
+    must be Join compatible by providing the following attributes and methods:
+        - table_name (string)
+        - table_alias (possible alias for the table, can be None)
+        - join_type (can be None for those entries that aren't joined from
+          anything)
+        - parent_alias (which table is this join's parent, can be None similarly
+          to join_type)
+        - as_sql()
+        - relabeled_clone()
+    """
+
+    def __init__(
+        self,
+        table_name,
+        parent_alias,
+        table_alias,
+        join_type,
+        join_field,
+        nullable,
+        filtered_relation=None,
+    ):
+        # Join table
+        self.table_name = table_name
+        self.parent_alias = parent_alias
+        # Note: table_alias is not necessarily known at instantiation time.
+        self.table_alias = table_alias
+        # LOUTER or INNER
+        self.join_type = join_type
+        # A list of 2-tuples to use in the ON clause of the JOIN.
+        # Each 2-tuple will create one join condition in the ON clause.
+        if hasattr(join_field, "get_joining_fields"):
+            self.join_fields = join_field.get_joining_fields()
+            self.join_cols = tuple(
+                (lhs_field.column, rhs_field.column)
+                for lhs_field, rhs_field in self.join_fields
+            )
+        else:
+            warnings.warn(
+                "The usage of get_joining_columns() in Join is deprecated. Implement "
+                "get_joining_fields() instead.",
+                RemovedInDjango60Warning,
+            )
+            self.join_fields = None
+            self.join_cols = join_field.get_joining_columns()
+        # Along which field (or ForeignObjectRel in the reverse join case)
+        self.join_field = join_field
+        # Is this join nullabled?
+        self.nullable = nullable
+        self.filtered_relation = filtered_relation
+
+    def as_sql(self, compiler, connection):
+        """
+        Generate the full
+           LEFT OUTER JOIN sometable ON sometable.somecol = othertable.othercol, params
+        clause for this join.
+        """
+        join_conditions = []
+        params = []
+        qn = compiler.quote_name_unless_alias
+        qn2 = connection.ops.quote_name
+        # Add a join condition for each pair of joining columns.
+        # RemovedInDjango60Warning: when the depraction ends, replace with:
+        # for lhs, rhs in self.join_field:
+        join_fields = self.join_fields or self.join_cols
+        for lhs, rhs in join_fields:
+            if isinstance(lhs, str):
+                # RemovedInDjango60Warning: when the depraction ends, remove
+                # the branch for strings.
+                lhs_full_name = "%s.%s" % (qn(self.parent_alias), qn2(lhs))
+                rhs_full_name = "%s.%s" % (qn(self.table_alias), qn2(rhs))
+            else:
+                lhs, rhs = connection.ops.prepare_join_on_clause(
+                    self.parent_alias, lhs, self.table_alias, rhs
+                )
+                lhs_sql, lhs_params = compiler.compile(lhs)
+                lhs_full_name = lhs_sql % lhs_params
+                rhs_sql, rhs_params = compiler.compile(rhs)
+                rhs_full_name = rhs_sql % rhs_params
+            join_conditions.append(f"{lhs_full_name} = {rhs_full_name}")
+
+        # Add a single condition inside parentheses for whatever
+        # get_extra_restriction() returns.
+        extra_cond = self.join_field.get_extra_restriction(
+            self.table_alias, self.parent_alias
+        )
+        if extra_cond:
+            extra_sql, extra_params = compiler.compile(extra_cond)
+            join_conditions.append("(%s)" % extra_sql)
+            params.extend(extra_params)
+        if self.filtered_relation:
+            try:
+                extra_sql, extra_params = compiler.compile(self.filtered_relation)
+            except FullResultSet:
+                pass
+            else:
+                join_conditions.append("(%s)" % extra_sql)
+                params.extend(extra_params)
+        if not join_conditions:
+            # This might be a rel on the other end of an actual declared field.
+            declared_field = getattr(self.join_field, "field", self.join_field)
+            raise ValueError(
+                "Join generated an empty ON clause. %s did not yield either "
+                "joining columns or extra restrictions." % declared_field.__class__
+            )
+        on_clause_sql = " AND ".join(join_conditions)
+        alias_str = (
+            "" if self.table_alias == self.table_name else (" %s" % self.table_alias)
+        )
+        sql = "%s %s%s ON (%s)" % (
+            self.join_type,
+            qn(self.table_name),
+            alias_str,
+            on_clause_sql,
+        )
+        return sql, params
+
+    def relabeled_clone(self, change_map):
+        new_parent_alias = change_map.get(self.parent_alias, self.parent_alias)
+        new_table_alias = change_map.get(self.table_alias, self.table_alias)
+        if self.filtered_relation is not None:
+            filtered_relation = self.filtered_relation.relabeled_clone(change_map)
+        else:
+            filtered_relation = None
+        return self.__class__(
+            self.table_name,
+            new_parent_alias,
+            new_table_alias,
+            self.join_type,
+            self.join_field,
+            self.nullable,
+            filtered_relation=filtered_relation,
+        )
+
+    @property
+    def identity(self):
+        return (
+            self.__class__,
+            self.table_name,
+            self.parent_alias,
+            self.join_field,
+            self.filtered_relation,
+        )
+
+    def __eq__(self, other):
+        if not isinstance(other, Join):
+            return NotImplemented
+        return self.identity == other.identity
+
+    def __hash__(self):
+        return hash(self.identity)
+
+    def demote(self):
+        new = self.relabeled_clone({})
+        new.join_type = INNER
+        return new
+
+    def promote(self):
+        new = self.relabeled_clone({})
+        new.join_type = LOUTER
+        return new
+
+
+class BaseTable:
+    """
+    The BaseTable class is used for base table references in FROM clause. For
+    example, the SQL "foo" in
+        SELECT * FROM "foo" WHERE somecond
+    could be generated by this class.
+    """
+
+    join_type = None
+    parent_alias = None
+    filtered_relation = None
+
+    def __init__(self, table_name, alias):
+        self.table_name = table_name
+        self.table_alias = alias
+
+    def as_sql(self, compiler, connection):
+        alias_str = (
+            "" if self.table_alias == self.table_name else (" %s" % self.table_alias)
+        )
+        base_sql = compiler.quote_name_unless_alias(self.table_name)
+        return base_sql + alias_str, []
+
+    def relabeled_clone(self, change_map):
+        return self.__class__(
+            self.table_name, change_map.get(self.table_alias, self.table_alias)
+        )
+
+    @property
+    def identity(self):
+        return self.__class__, self.table_name, self.table_alias
+
+    def __eq__(self, other):
+        if not isinstance(other, BaseTable):
+            return NotImplemented
+        return self.identity == other.identity
+
+    def __hash__(self):
+        return hash(self.identity)

myenv/lib/python3.12/site-packages/django/db/models/sql/subqueries.py

@@ -0,0 +1,178 @@
+"""
+Query subclasses which provide extra functionality beyond simple data retrieval.
+"""
+
+from django.core.exceptions import FieldError
+from django.db.models.sql.constants import (
+    GET_ITERATOR_CHUNK_SIZE,
+    NO_RESULTS,
+    ROW_COUNT,
+)
+from django.db.models.sql.query import Query
+
+__all__ = ["DeleteQuery", "UpdateQuery", "InsertQuery", "AggregateQuery"]
+
+
+class DeleteQuery(Query):
+    """A DELETE SQL query."""
+
+    compiler = "SQLDeleteCompiler"
+
+    def do_query(self, table, where, using):
+        self.alias_map = {table: self.alias_map[table]}
+        self.where = where
+        return self.get_compiler(using).execute_sql(ROW_COUNT)
+
+    def delete_batch(self, pk_list, using):
+        """
+        Set up and execute delete queries for all the objects in pk_list.
+
+        More than one physical query may be executed if there are a
+        lot of values in pk_list.
+        """
+        # number of objects deleted
+        num_deleted = 0
+        field = self.get_meta().pk
+        for offset in range(0, len(pk_list), GET_ITERATOR_CHUNK_SIZE):
+            self.clear_where()
+            self.add_filter(
+                f"{field.attname}__in",
+                pk_list[offset : offset + GET_ITERATOR_CHUNK_SIZE],
+            )
+            num_deleted += self.do_query(
+                self.get_meta().db_table, self.where, using=using
+            )
+        return num_deleted
+
+
+class UpdateQuery(Query):
+    """An UPDATE SQL query."""
+
+    compiler = "SQLUpdateCompiler"
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self._setup_query()
+
+    def _setup_query(self):
+        """
+        Run on initialization and at the end of chaining. Any attributes that
+        would normally be set in __init__() should go here instead.
+        """
+        self.values = []
+        self.related_ids = None
+        self.related_updates = {}
+
+    def clone(self):
+        obj = super().clone()
+        obj.related_updates = self.related_updates.copy()
+        return obj
+
+    def update_batch(self, pk_list, values, using):
+        self.add_update_values(values)
+        for offset in range(0, len(pk_list), GET_ITERATOR_CHUNK_SIZE):
+            self.clear_where()
+            self.add_filter(
+                "pk__in", pk_list[offset : offset + GET_ITERATOR_CHUNK_SIZE]
+            )
+            self.get_compiler(using).execute_sql(NO_RESULTS)
+
+    def add_update_values(self, values):
+        """
+        Convert a dictionary of field name to value mappings into an update
+        query. This is the entry point for the public update() method on
+        querysets.
+        """
+        values_seq = []
+        for name, val in values.items():
+            field = self.get_meta().get_field(name)
+            direct = (
+                not (field.auto_created and not field.concrete) or not field.concrete
+            )
+            model = field.model._meta.concrete_model
+            if field.name == "pk" and model._meta.is_composite_pk:
+                raise FieldError(
+                    "Composite primary key fields must be updated individually."
+                )
+            if not direct or (field.is_relation and field.many_to_many):
+                raise FieldError(
+                    "Cannot update model field %r (only non-relations and "
+                    "foreign keys permitted)." % field
+                )
+            if model is not self.get_meta().concrete_model:
+                self.add_related_update(model, field, val)
+                continue
+            values_seq.append((field, model, val))
+        return self.add_update_fields(values_seq)
+
+    def add_update_fields(self, values_seq):
+        """
+        Append a sequence of (field, model, value) triples to the internal list
+        that will be used to generate the UPDATE query. Might be more usefully
+        called add_update_targets() to hint at the extra information here.
+        """
+        for field, model, val in values_seq:
+            # Omit generated fields.
+            if field.generated:
+                continue
+            if hasattr(val, "resolve_expression"):
+                # Resolve expressions here so that annotations are no longer needed
+                val = val.resolve_expression(self, allow_joins=False, for_save=True)
+            self.values.append((field, model, val))
+
+    def add_related_update(self, model, field, value):
+        """
+        Add (name, value) to an update query for an ancestor model.
+
+        Update are coalesced so that only one update query per ancestor is run.
+        """
+        self.related_updates.setdefault(model, []).append((field, None, value))
+
+    def get_related_updates(self):
+        """
+        Return a list of query objects: one for each update required to an
+        ancestor model. Each query will have the same filtering conditions as
+        the current query but will only update a single table.
+        """
+        if not self.related_updates:
+            return []
+        result = []
+        for model, values in self.related_updates.items():
+            query = UpdateQuery(model)
+            query.values = values
+            if self.related_ids is not None:
+                query.add_filter("pk__in", self.related_ids[model])
+            result.append(query)
+        return result
+
+
+class InsertQuery(Query):
+    compiler = "SQLInsertCompiler"
+
+    def __init__(
+        self, *args, on_conflict=None, update_fields=None, unique_fields=None, **kwargs
+    ):
+        super().__init__(*args, **kwargs)
+        self.fields = []
+        self.objs = []
+        self.on_conflict = on_conflict
+        self.update_fields = update_fields or []
+        self.unique_fields = unique_fields or []
+
+    def insert_values(self, fields, objs, raw=False):
+        self.fields = fields
+        self.objs = objs
+        self.raw = raw
+
+
+class AggregateQuery(Query):
+    """
+    Take another query as a parameter to the FROM clause and only select the
+    elements in the provided list.
+    """
+
+    compiler = "SQLAggregateCompiler"
+
+    def __init__(self, model, inner_query):
+        self.inner_query = inner_query
+        super().__init__(model)

myenv/lib/python3.12/site-packages/django/db/models/sql/where.py

@@ -0,0 +1,345 @@
+"""
+Code to manage the creation and SQL rendering of 'where' constraints.
+"""
+
+import operator
+from functools import reduce
+
+from django.core.exceptions import EmptyResultSet, FullResultSet
+from django.db.models.expressions import Case, When
+from django.db.models.functions import Mod
+from django.db.models.lookups import Exact
+from django.utils import tree
+from django.utils.functional import cached_property
+
+# Connection types
+AND = "AND"
+OR = "OR"
+XOR = "XOR"
+
+
+class WhereNode(tree.Node):
+    """
+    An SQL WHERE clause.
+
+    The class is tied to the Query class that created it (in order to create
+    the correct SQL).
+
+    A child is usually an expression producing boolean values. Most likely the
+    expression is a Lookup instance.
+
+    However, a child could also be any class with as_sql() and either
+    relabeled_clone() method or relabel_aliases() and clone() methods and
+    contains_aggregate attribute.
+    """
+
+    default = AND
+    resolved = False
+    conditional = True
+
+    def split_having_qualify(self, negated=False, must_group_by=False):
+        """
+        Return three possibly None nodes: one for those parts of self that
+        should be included in the WHERE clause, one for those parts of self
+        that must be included in the HAVING clause, and one for those parts
+        that refer to window functions.
+        """
+        if not self.contains_aggregate and not self.contains_over_clause:
+            return self, None, None
+        in_negated = negated ^ self.negated
+        # Whether or not children must be connected in the same filtering
+        # clause (WHERE > HAVING > QUALIFY) to maintain logical semantic.
+        must_remain_connected = (
+            (in_negated and self.connector == AND)
+            or (not in_negated and self.connector == OR)
+            or self.connector == XOR
+        )
+        if (
+            must_remain_connected
+            and self.contains_aggregate
+            and not self.contains_over_clause
+        ):
+            # It's must cheaper to short-circuit and stash everything in the
+            # HAVING clause than split children if possible.
+            return None, self, None
+        where_parts = []
+        having_parts = []
+        qualify_parts = []
+        for c in self.children:
+            if hasattr(c, "split_having_qualify"):
+                where_part, having_part, qualify_part = c.split_having_qualify(
+                    in_negated, must_group_by
+                )
+                if where_part is not None:
+                    where_parts.append(where_part)
+                if having_part is not None:
+                    having_parts.append(having_part)
+                if qualify_part is not None:
+                    qualify_parts.append(qualify_part)
+            elif c.contains_over_clause:
+                qualify_parts.append(c)
+            elif c.contains_aggregate:
+                having_parts.append(c)
+            else:
+                where_parts.append(c)
+        if must_remain_connected and qualify_parts:
+            # Disjunctive heterogeneous predicates can be pushed down to
+            # qualify as long as no conditional aggregation is involved.
+            if not where_parts or (where_parts and not must_group_by):
+                return None, None, self
+            elif where_parts:
+                # In theory this should only be enforced when dealing with
+                # where_parts containing predicates against multi-valued
+                # relationships that could affect aggregation results but this
+                # is complex to infer properly.
+                raise NotImplementedError(
+                    "Heterogeneous disjunctive predicates against window functions are "
+                    "not implemented when performing conditional aggregation."
+                )
+        where_node = (
+            self.create(where_parts, self.connector, self.negated)
+            if where_parts
+            else None
+        )
+        having_node = (
+            self.create(having_parts, self.connector, self.negated)
+            if having_parts
+            else None
+        )
+        qualify_node = (
+            self.create(qualify_parts, self.connector, self.negated)
+            if qualify_parts
+            else None
+        )
+        return where_node, having_node, qualify_node
+
+    def as_sql(self, compiler, connection):
+        """
+        Return the SQL version of the where clause and the value to be
+        substituted in. Return '', [] if this node matches everything,
+        None, [] if this node is empty, and raise EmptyResultSet if this
+        node can't match anything.
+        """
+        result = []
+        result_params = []
+        if self.connector == AND:
+            full_needed, empty_needed = len(self.children), 1
+        else:
+            full_needed, empty_needed = 1, len(self.children)
+
+        if self.connector == XOR and not connection.features.supports_logical_xor:
+            # Convert if the database doesn't support XOR:
+            #   a XOR b XOR c XOR ...
+            # to:
+            #   (a OR b OR c OR ...) AND MOD(a + b + c + ..., 2) == 1
+            # The result of an n-ary XOR is true when an odd number of operands
+            # are true.
+            lhs = self.__class__(self.children, OR)
+            rhs_sum = reduce(
+                operator.add,
+                (Case(When(c, then=1), default=0) for c in self.children),
+            )
+            if len(self.children) > 2:
+                rhs_sum = Mod(rhs_sum, 2)
+            rhs = Exact(1, rhs_sum)
+            return self.__class__([lhs, rhs], AND, self.negated).as_sql(
+                compiler, connection
+            )
+
+        for child in self.children:
+            try:
+                sql, params = compiler.compile(child)
+            except EmptyResultSet:
+                empty_needed -= 1
+            except FullResultSet:
+                full_needed -= 1
+            else:
+                if sql:
+                    result.append(sql)
+                    result_params.extend(params)
+                else:
+                    full_needed -= 1
+            # Check if this node matches nothing or everything.
+            # First check the amount of full nodes and empty nodes
+            # to make this node empty/full.
+            # Now, check if this node is full/empty using the
+            # counts.
+            if empty_needed == 0:
+                if self.negated:
+                    raise FullResultSet
+                else:
+                    raise EmptyResultSet
+            if full_needed == 0:
+                if self.negated:
+                    raise EmptyResultSet
+                else:
+                    raise FullResultSet
+        conn = " %s " % self.connector
+        sql_string = conn.join(result)
+        if not sql_string:
+            raise FullResultSet
+        if self.negated:
+            # Some backends (Oracle at least) need parentheses around the inner
+            # SQL in the negated case, even if the inner SQL contains just a
+            # single expression.
+            sql_string = "NOT (%s)" % sql_string
+        elif len(result) > 1 or self.resolved:
+            sql_string = "(%s)" % sql_string
+        return sql_string, result_params
+
+    def get_group_by_cols(self):
+        cols = []
+        for child in self.children:
+            cols.extend(child.get_group_by_cols())
+        return cols
+
+    def get_source_expressions(self):
+        return self.children[:]
+
+    def set_source_expressions(self, children):
+        assert len(children) == len(self.children)
+        self.children = children
+
+    def relabel_aliases(self, change_map):
+        """
+        Relabel the alias values of any children. 'change_map' is a dictionary
+        mapping old (current) alias values to the new values.
+        """
+        if not change_map:
+            return self
+        for pos, child in enumerate(self.children):
+            if hasattr(child, "relabel_aliases"):
+                # For example another WhereNode
+                child.relabel_aliases(change_map)
+            elif hasattr(child, "relabeled_clone"):
+                self.children[pos] = child.relabeled_clone(change_map)
+
+    def clone(self):
+        clone = self.create(connector=self.connector, negated=self.negated)
+        for child in self.children:
+            if hasattr(child, "clone"):
+                child = child.clone()
+            clone.children.append(child)
+        return clone
+
+    def relabeled_clone(self, change_map):
+        clone = self.clone()
+        clone.relabel_aliases(change_map)
+        return clone
+
+    def replace_expressions(self, replacements):
+        if not replacements:
+            return self
+        if replacement := replacements.get(self):
+            return replacement
+        clone = self.create(connector=self.connector, negated=self.negated)
+        for child in self.children:
+            clone.children.append(child.replace_expressions(replacements))
+        return clone
+
+    def get_refs(self):
+        refs = set()
+        for child in self.children:
+            refs |= child.get_refs()
+        return refs
+
+    @classmethod
+    def _contains_aggregate(cls, obj):
+        if isinstance(obj, tree.Node):
+            return any(cls._contains_aggregate(c) for c in obj.children)
+        return obj.contains_aggregate
+
+    @cached_property
+    def contains_aggregate(self):
+        return self._contains_aggregate(self)
+
+    @classmethod
+    def _contains_over_clause(cls, obj):
+        if isinstance(obj, tree.Node):
+            return any(cls._contains_over_clause(c) for c in obj.children)
+        return obj.contains_over_clause
+
+    @cached_property
+    def contains_over_clause(self):
+        return self._contains_over_clause(self)
+
+    @property
+    def is_summary(self):
+        return any(child.is_summary for child in self.children)
+
+    @staticmethod
+    def _resolve_leaf(expr, query, *args, **kwargs):
+        if hasattr(expr, "resolve_expression"):
+            expr = expr.resolve_expression(query, *args, **kwargs)
+        return expr
+
+    @classmethod
+    def _resolve_node(cls, node, query, *args, **kwargs):
+        if hasattr(node, "children"):
+            for child in node.children:
+                cls._resolve_node(child, query, *args, **kwargs)
+        if hasattr(node, "lhs"):
+            node.lhs = cls._resolve_leaf(node.lhs, query, *args, **kwargs)
+        if hasattr(node, "rhs"):
+            node.rhs = cls._resolve_leaf(node.rhs, query, *args, **kwargs)
+
+    def resolve_expression(self, *args, **kwargs):
+        clone = self.clone()
+        clone._resolve_node(clone, *args, **kwargs)
+        clone.resolved = True
+        return clone
+
+    @cached_property
+    def output_field(self):
+        from django.db.models import BooleanField
+
+        return BooleanField()
+
+    @property
+    def _output_field_or_none(self):
+        return self.output_field
+
+    def select_format(self, compiler, sql, params):
+        # Wrap filters with a CASE WHEN expression if a database backend
+        # (e.g. Oracle) doesn't support boolean expression in SELECT or GROUP
+        # BY list.
+        if not compiler.connection.features.supports_boolean_expr_in_select_clause:
+            sql = f"CASE WHEN {sql} THEN 1 ELSE 0 END"
+        return sql, params
+
+    def get_db_converters(self, connection):
+        return self.output_field.get_db_converters(connection)
+
+    def get_lookup(self, lookup):
+        return self.output_field.get_lookup(lookup)
+
+    def leaves(self):
+        for child in self.children:
+            if isinstance(child, WhereNode):
+                yield from child.leaves()
+            else:
+                yield child
+
+
+class NothingNode:
+    """A node that matches nothing."""
+
+    contains_aggregate = False
+    contains_over_clause = False
+
+    def as_sql(self, compiler=None, connection=None):
+        raise EmptyResultSet
+
+
+class ExtraWhere:
+    # The contents are a black box - assume no aggregates or windows are used.
+    contains_aggregate = False
+    contains_over_clause = False
+
+    def __init__(self, sqls, params):
+        self.sqls = sqls
+        self.params = params
+
+    def as_sql(self, compiler=None, connection=None):
+        sqls = ["(%s)" % sql for sql in self.sqls]
+        return " AND ".join(sqls), list(self.params or ())