diff --git a/frappe/desk/doctype/route_history/route_history.py b/frappe/desk/doctype/route_history/route_history.py
index f0aa867c8a..bb10fb08f2 100644
--- a/frappe/desk/doctype/route_history/route_history.py
+++ b/frappe/desk/doctype/route_history/route_history.py
@@ -1,11 +1,11 @@
-# Copyright (c) 2021, Frappe Technologies and contributors
+# Copyright (c) 2022, Frappe Technologies and contributors
 # License: MIT. See LICENSE
 
-import json
-
 import frappe
 from frappe.deferred_insert import deferred_insert as _deferred_insert
 from frappe.model.document import Document
+from frappe.query_builder.utils import DocType
+from frappe.query_builder.functions import Count
 
 
 class RouteHistory(Document):
@@ -14,31 +14,31 @@ class RouteHistory(Document):
 
 def flush_old_route_records():
 	"""Deletes all route records except last 500 records per user"""
-
 	records_to_keep_limit = 500
-	users = frappe.db.sql('''
-		SELECT `user`
-		FROM `tabRoute History`
-		GROUP BY `user`
-		HAVING count(`name`) > %(limit)s
-	''', {
-		"limit": records_to_keep_limit
-	})
+	RouteHistory = DocType("Route History")
+
+	users = (
+		frappe.qb.from_(RouteHistory)
+		.select(RouteHistory.user)
+		.groupby(RouteHistory.user)
+		.having(Count(RouteHistory.name) > records_to_keep_limit)
+	).run(pluck=True)
 
 	for user in users:
-		user = user[0]
-		last_record_to_keep = frappe.db.get_all('Route History',
-			filters={'user': user},
-			limit=1,
+		last_record_to_keep = frappe.get_all(
+			"Route History",
+			filters={"user": user},
 			limit_start=500,
-			fields=['modified'],
-			order_by='modified desc'
+			fields=["modified"],
+			order_by="modified desc",
+			limit=1,
+		)
+
+		frappe.db.delete(
+			"Route History",
+			{"modified": ("<=", last_record_to_keep[0].modified), "user": user},
 		)
 
-		frappe.db.delete("Route History", {
-			"modified": ("<=", last_record_to_keep[0].modified),
-			"user": user
-		})
 
 @frappe.whitelist()
 def deferred_insert(routes):
@@ -51,10 +51,16 @@ def deferred_insert(routes):
 		for route in frappe.parse_json(routes)
 	]
 
-	_deferred_insert("Route History", json.dumps(routes))
+	_deferred_insert("Route History", routes)
+
 
 @frappe.whitelist()
 def frequently_visited_links():
-	return frappe.get_all('Route History', fields=['route', 'count(name) as count'], filters={
-		'user': frappe.session.user
-	}, group_by="route", order_by="count desc", limit=5)
+	return frappe.get_all(
+		"Route History",
+		fields=["route", "count(name) as count"],
+		filters={"user": frappe.session.user},
+		group_by="route",
+		order_by="count desc",
+		limit=5,
+	)