Index: database.sql
==================================================================
--- database.sql
+++ database.sql
@@ -87,10 +87,26 @@
 		select id_tag from tag where usort(my_tag) = tag into tag_id;
 	end if;
 	return tag_id;
 end;
 $$;
+
+-- this function returns id of site array
+create or replace function get_site(my_site text[]) returns integer
+	language plpgsql strict
+	as $$
+declare
+	site_id integer;
+begin
+	select id_site from site where my_site = site into site_id;
+	if not found then
+		insert into site (site) values (my_site);
+		select id_site from site where my_site = site into site_id;
+	end if;
+	return site_id;
+end;
+$$;
 
 -- transforms domain into ordered array for indexing
 CREATE FUNCTION tripdomain(url text) RETURNS text[]
 	LANGUAGE plpgsql IMMUTABLE STRICT
 	AS $_$