start using HAVING instead of manually building joins

lib/pg_searchable_regex.rb

@@ -55,16 +55,14 @@ module PgSearchable
 
     def ts_search(value)
       return if @ts_search_fields.blank? || value.blank?
-      model = ancestors.first
       sql_query_object = TextToSqlQuery.new(
         value,
         @ts_search_fields,
         @default_fields,
         @ts_search_fields_mappings,
-        @ts_joins,
-        model
+        @ts_joins
       )
-      joins(sql_query_object.join_clause).where(sql_query_object.where_clause).distinct
+      distinct.joins(sql_query_object.join_clause).group(:id).having(sql_query_object.where_clause)
     end
 
     def should_update_cache_field?