수파베이스 에러 syntax error at or near "select"

ERROR:  syntax error at or near "select"
LINE 1: create policy "Policy with table joins" on "public"."userthema" as 
permissive for update to public using 
(select dogthemabgdb.themabg from dogthemabgdb where dogthemabgdb.themaurl = userthema.themaurl);

 

sql 문법 오류

using 절에 있는 서브쿼리에서 에러 발생

create policy "Policy with table joins" 
on "public"."userthema" 
as permissive 
for update 
to public 
using (
    select dogthemabgdb.themabg 
    from dogthemabgdb 
    where dogthemabgdb.themaurl = userthema.themaurl
);