diff --git a/debug_toolbar/panels/sql/panel.py b/debug_toolbar/panels/sql/panel.py
index c8576e16f..984a2074a 100644
--- a/debug_toolbar/panels/sql/panel.py
+++ b/debug_toolbar/panels/sql/panel.py
@@ -6,6 +6,7 @@
 from django.urls import path
 from django.utils.translation import gettext_lazy as _, ngettext
 
+from debug_toolbar import settings as dt_settings
 from debug_toolbar.forms import SignedDataForm
 from debug_toolbar.panels import Panel
 from debug_toolbar.panels.sql import views
@@ -110,9 +111,7 @@ class SQLPanel(Panel):
 
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
-        self._offset = {k: len(connections[k].queries) for k in connections}
         self._sql_time = 0
-        self._num_queries = 0
         self._queries = []
         self._databases = {}
         # synthetic transaction IDs, keyed by DB alias
@@ -151,7 +150,6 @@ def record(self, **kwargs):
             self._databases[alias]["time_spent"] += kwargs["duration"]
             self._databases[alias]["num_queries"] += 1
         self._sql_time += kwargs["duration"]
-        self._num_queries += 1
 
     # Implement the Panel API
 
@@ -159,12 +157,13 @@ def record(self, **kwargs):
 
     @property
     def nav_subtitle(self):
+        query_count = len(self._queries)
         return ngettext(
             "%(query_count)d query in %(sql_time).2fms",
             "%(query_count)d queries in %(sql_time).2fms",
-            self._num_queries,
+            query_count,
         ) % {
-            "query_count": self._num_queries,
+            "query_count": query_count,
             "sql_time": self._sql_time,
         }
 
@@ -204,6 +203,8 @@ def generate_stats(self, request, response):
         duplicate_query_groups = defaultdict(list)
 
         if self._queries:
+            sql_warning_threshold = dt_settings.get_config()["SQL_WARNING_THRESHOLD"]
+
             width_ratio_tally = 0
             factor = int(256.0 / (len(self._databases) * 2.5))
             for n, db in enumerate(self._databases.values()):
@@ -261,6 +262,12 @@ def generate_stats(self, request, response):
 
                 if query["sql"]:
                     query["sql"] = reformat_sql(query["sql"], with_toggle=True)
+
+                query["is_slow"] = query["duration"] > sql_warning_threshold
+                query["is_select"] = (
+                    query["raw_sql"].lower().lstrip().startswith("select")
+                )
+
                 query["rgb_color"] = self._databases[alias]["rgb_color"]
                 try:
                     query["width_ratio"] = (query["duration"] / self._sql_time) * 100
diff --git a/debug_toolbar/panels/sql/tracking.py b/debug_toolbar/panels/sql/tracking.py
index a85ac51ad..ee75f8e06 100644
--- a/debug_toolbar/panels/sql/tracking.py
+++ b/debug_toolbar/panels/sql/tracking.py
@@ -7,7 +7,6 @@
 from django.db.backends.utils import CursorWrapper
 from django.utils.encoding import force_str
 
-from debug_toolbar import settings as dt_settings
 from debug_toolbar.utils import get_stack_trace, get_template_info
 
 try:
@@ -34,8 +33,14 @@ class SQLQueryTriggered(Exception):
 
 
 def wrap_cursor(connection):
-    # If running a Django SimpleTestCase, which isn't allowed to access the database,
-    # don't perform any monkey patching.
+    # When running a SimpleTestCase, Django monkey patches some DatabaseWrapper
+    # methods, including .cursor() and .chunked_cursor(), to raise an exception
+    # if the test code tries to access the database, and then undoes the monkey
+    # patching when the test case is finished.  If we monkey patch those methods
+    # also, Django's process of undoing those monkey patches will fail.  To
+    # avoid this failure, and because database access is not allowed during a
+    # SimpleTextCase anyway, skip applying our instrumentation monkey patches if
+    # we detect that Django has already monkey patched DatabaseWrapper.cursor().
     if isinstance(connection.cursor, django.test.testcases._DatabaseFailure):
         return
     if not hasattr(connection, "_djdt_cursor"):
@@ -182,7 +187,7 @@ def _record(self, method, sql, params):
             else:
                 sql = str(sql)
 
-            params = {
+            kwargs = {
                 "vendor": vendor,
                 "alias": alias,
                 "sql": self._last_executed_query(sql, params),
@@ -191,12 +196,6 @@ def _record(self, method, sql, params):
                 "params": _params,
                 "raw_params": params,
                 "stacktrace": get_stack_trace(skip=2),
-                "start_time": start_time,
-                "stop_time": stop_time,
-                "is_slow": (
-                    duration > dt_settings.get_config()["SQL_WARNING_THRESHOLD"]
-                ),
-                "is_select": sql.lower().strip().startswith("select"),
                 "template_info": template_info,
             }
 
@@ -228,7 +227,7 @@ def _record(self, method, sql, params):
                 else:
                     trans_id = None
 
-                params.update(
+                kwargs.update(
                     {
                         "trans_id": trans_id,
                         "trans_status": conn.info.transaction_status,
@@ -237,7 +236,7 @@ def _record(self, method, sql, params):
                 )
 
             # We keep `sql` to maintain backwards compatibility
-            self.logger.record(**params)
+            self.logger.record(**kwargs)
 
     def callproc(self, procname, params=None):
         return self._record(super().callproc, procname, params)