[5.2.x] Refs #36181 -- Removed the obsolete SubqueryConstraint machinery.

Adding proper support for subquery right-hand-sides to TupleIn made it
obsolete.

Backport of d386405e04dac50656af50d100a14efdf8c58e8f from main

Co-authored-by: Simon Charette <charette.s@gmail.com>

2 files changed, 0 insertions, 34 deletions

diff --git a/django/db/models/sql/compiler.py b/django/db/models/sql/compiler.py
index 04372c509e..0b6cfbfc37 100644
--- a/django/db/models/sql/compiler.py
+++ b/django/db/models/sql/compiler.py
@@ -22,7 +22,6 @@ from django.db.models.sql.constants import (
     SINGLE,
 )
 from django.db.models.sql.query import Query, get_order_dir
-from django.db.models.sql.where import AND
 from django.db.transaction import TransactionManagementError
 from django.utils.functional import cached_property
 from django.utils.hashable import make_hashable
@@ -1661,19 +1660,6 @@ class SQLCompiler:
             return list(result)
         return result
 
-    def as_subquery_condition(self, alias, columns, compiler):
-        qn = compiler.quote_name_unless_alias
-        qn2 = self.connection.ops.quote_name
-        query = self.query.clone()
-
-        for index, select_col in enumerate(query.select):
-            lhs_sql, lhs_params = self.compile(select_col)
-            rhs = "%s.%s" % (qn(alias), qn2(columns[index]))
-            query.where.add(RawSQL("%s = %s" % (lhs_sql, rhs), lhs_params), AND)
-
-        sql, params = query.as_sql(compiler, self.connection)
-        return "EXISTS %s" % sql, params
-
     def explain_query(self):
         result = list(self.execute_sql())
         # Some backends return 1 item tuples with strings, and others return
diff --git a/django/db/models/sql/where.py b/django/db/models/sql/where.py
index 0fded5cce3..82f96aa6ec 100644
--- a/django/db/models/sql/where.py
+++ b/django/db/models/sql/where.py
@@ -343,23 +343,3 @@ class ExtraWhere:
     def as_sql(self, compiler=None, connection=None):
         sqls = ["(%s)" % sql for sql in self.sqls]
         return " AND ".join(sqls), list(self.params or ())
-
-
-class SubqueryConstraint:
-    # Even if aggregates or windows would be used in a subquery,
-    # the outer query isn't interested about those.
-    contains_aggregate = False
-    contains_over_clause = False
-
-    def __init__(self, alias, columns, targets, query_object):
-        self.alias = alias
-        self.columns = columns
-        self.targets = targets
-        query_object.clear_ordering(clear_default=True)
-        self.query_object = query_object
-
-    def as_sql(self, compiler, connection):
-        query = self.query_object
-        query.set_values(self.targets)
-        query_compiler = query.get_compiler(connection=connection)
-        return query_compiler.as_subquery_condition(self.alias, self.columns, compiler)