diff --git a/app/models/city.rb b/app/models/city.rb
index 8f5e73f..4d7f95b 100644
--- a/app/models/city.rb
+++ b/app/models/city.rb
@@ -42,14 +42,14 @@ class City < ApplicationRecord
     # 根据数据库类型构建不同的查询
     base_query = if ActiveRecord::Base.connection.adapter_name.downcase == "sqlite"
                    joins(<<-SQL.squish)
-      LEFT JOIN ahoy_events ON 
+      LEFT JOIN ahoy_events ON#{' '}
         json_extract(ahoy_events.properties, '$.city_id') = cities.id
         AND json_extract(ahoy_events.properties, '$.event_type') = 'city_view'
         AND ahoy_events.time > '#{start_time}'
     SQL
     else
                    joins(<<-SQL.squish)
-      LEFT JOIN ahoy_events ON 
+      LEFT JOIN ahoy_events ON#{' '}
         (ahoy_events.properties::jsonb->>'city_id')::integer = cities.id
         AND ahoy_events.properties::jsonb->>'event_type' = 'city_view'
         AND ahoy_events.time > '#{start_time}'