利用over开窗函数取第一条记录

SQL> set linesize 200

SQL> select * from (select a.* ,row_number() over( order by empno) rn  from emp a)

where rn=1  2 

  3  ;

EMPNO ENAME      JOB        MGR HIREDATE     SAL       COMM     DEPTNO DNAME        RN

---------- ---------- --------- ---------- --------- ---------- ---------- ---------- -------------------------------------------------- ----------

      7369 SMITH      CLERK       7902 17-DEC-80     800      20 UFO