Fix 'flush_old_route_record' code

frappe/desk/doctype/route_history/route_history.py

@@ -12,11 +12,9 @@ class RouteHistory(Document):
 
 @frappe.whitelist()
 def save_route_history(routes):
-	# print('Dump history---------------------------')
 	frappe.cache().rpush('route_history', routes)
 
 def save_route_history_to_db():
-	# print('================================= Saving Route History')
 	values = []
 	while frappe.cache().llen('route_history') > 0:
 		routes = frappe.cache().lpop('route_history')
@@ -37,9 +35,29 @@ def save_route_history_to_db():
 	frappe.db.commit()
 
 def flush_old_route_records():
-	frappe.db.sql('''
-		SELECT `user`, count(`name`) AS count
+	"""Deletes all route records except last 500 records per user"""
+
+	records_to_keep_limit = 500
+	users = frappe.db.sql('''
+		SELECT `user`
 		FROM `tabRoute History`
-		WHERE count > 20
-		GROUP BY `name`
-	''')
+		GROUP BY `user`
+		HAVING count(`name`) > {limit}
+	'''.format(limit=records_to_keep_limit))
+
+	for user in users:
+		user = user[0]
+		last_record_to_keep = frappe.db.get_all('Route History',
+			filters={
+				'user': user,
+			},
+			limit=1,
+			limit_start=500,
+			fields=['modified'],
+			order_by='modified desc')
+
+		frappe.db.sql('''
+			DELETE
+			FROM `tabRoute History`
+			WHERE `modified` <= '{modified}' and `user`='{user}'
+		'''.format(modified=last_record_to_keep[0].modified, user=user))