--debug-sql fails on Oracle if a query with params fails to execute and no prior query has either

[Jacob Walls]

Noticed while working on ticket:35972 that an Oracle failure I wanted to debug with --debug-sql failed like:

======================================================================
ERROR: test_last_executed_query_without_previous_query (backends.tests.LastExecutedQueryTest)
last_executed_query should not raise an exception even if no previous
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/django/source/tests/backends/tests.py", line 80, in test_last_executed_query_without_previous_query
    connection.ops.last_executed_query(cursor, "SELECT %s;", (1,))
  File "/django/source/django/db/backends/oracle/operations.py", line 330, in last_executed_query
    statement = statement.replace(
AttributeError: 'NoneType' object has no attribute 'replace'

Failing test:

tests/backends/tests.py

@@ -19 +19 @@
 from django.db.backends.base.base import BaseDatabaseWrapper
 from django.db.backends.signals import connection_created
 from django.db.backends.utils import CursorWrapper
 from django.db.models.sql.constants import CURSOR
 from django.test import (
     TestCase,
@@ -74 +75 @@
         query has been run.
         """
         with connection.cursor() as cursor:
-            connection.ops.last_executed_query(cursor, "", ())
+            if connection.vendor == "oracle":
+                cursor.statement = None
+            connection.ops.last_executed_query(cursor, "SELECT %s;", (1,))
 
     def test_debug_sql(self):
         list(Reporter.objects.filter(first_name="test"))

The actual failure (where cursor.statement was None) happened via making this copy-paste mistake from the as_sql() method before it:

django/db/models/fields/json.py

@@ -252 +252 @@
             # queries but it is assumed that it cannot be evaded because the
             # path is JSON serialized.
             sql_parts.append(template % (lhs_sql, rhs_json_path))
-            params.extend(lhs_params)
+            params.extend(list(lhs_params) + [rhs_json_path])
         return self._combine_sql_parts(sql_parts), tuple(params)
 
     def as_postgresql(self, compiler, connection):

[Jacob Walls]

​PR