아래와 같은 스칼라 서브 쿼리 형태도 PostgreSQL 에서 잘 수행됩니다.
select e.empno, e.ename, (select dname from dept d where e.deptno=d.deptno) from emp e;
scott@[local]:5432 scottdb#SQL> select e.empno, e.ename, (select dname from dept d where e.deptno=d.deptno) from emp e;
-------+--------+------------
7782 | CLARK | ACCOUNTING
7934 | MILLER | ACCOUNTING
scott@[local]:5432 scottdb#SQL>
