Fixed #36085 -- Added JSONField support for negative array indexing on SQLite.

django/db/backends/base/features.py

@@ -347,6 +347,8 @@ class BaseDatabaseFeatures:
     json_key_contains_list_matching_requires_list = False
     # Does the backend support JSONObject() database function?
     has_json_object_function = True
+    # Does the backend support negative JSON array indexing?
+    supports_json_negative_indexing = True
 
     # Does the backend support column collations?
     supports_collation_on_charfield = True

django/db/backends/base/operations.py

@@ -793,6 +793,12 @@ class BaseDatabaseOperations:
         # Hook for backends (e.g. NoSQL) to customize formatting.
         return sqlparse.format(sql, reindent=True, keyword_case="upper")
 
+    def format_json_path_numeric_index(self, num):
+        """
+        Hook for backends to customize array indexing in JSON paths.
+        """
+        return "[%s]" % num
+
     def compile_json_path(self, key_transforms, include_root=True):
         """
         Hook for backends to customize all aspects of JSON path construction.
@@ -805,5 +811,13 @@ class BaseDatabaseOperations:
                 path.append(".")
                 path.append(json.dumps(key_transform))
             else:
-                path.append("[%s]" % num)
+                if (
+                    num < 0
+                    and not self.connection.features.supports_json_negative_indexing
+                ):
+                    raise NotSupportedError(
+                        "Using negative JSON array indices is not supported on this "
+                        "database backend."
+                    )
+                path.append(self.format_json_path_numeric_index(num))
         return "".join(path)

django/db/backends/mysql/features.py

@@ -58,6 +58,8 @@ class DatabaseFeatures(BaseDatabaseFeatures):
     supports_stored_generated_columns = True
     supports_virtual_generated_columns = True
 
+    supports_json_negative_indexing = False
+
     @cached_property
     def minimum_database_version(self):
         if self.connection.mysql_is_mariadb:

django/db/backends/oracle/features.py

@@ -73,6 +73,7 @@ class DatabaseFeatures(BaseDatabaseFeatures):
     requires_compound_order_by_subquery = True
     allows_multiple_constraints_on_same_fields = False
     supports_json_field_contains = False
+    supports_json_negative_indexing = False
     supports_collation_on_textfield = False
     test_now_utc_template = "CURRENT_TIMESTAMP AT TIME ZONE 'UTC'"
     django_test_expected_failures = {

django/db/backends/sqlite3/operations.py

@@ -441,3 +441,6 @@ class DatabaseOperations(BaseDatabaseOperations):
 
     def force_group_by(self):
         return ["GROUP BY TRUE"] if Database.sqlite_version_info < (3, 39) else []
+
+    def format_json_path_numeric_index(self, num):
+        return "[#%s]" % num if num < 0 else super().format_json_path_numeric_index(num)