ROWNUM伪列
vastbase=# select rownum,empno,ename from emp;
rownum | empno | ename
--------+-------+--------
1 | 7369 | SMITH
2 | 7499 | ALLEN
3 | 7521 | WARD
4 | 7566 | JONES
5 | 7654 | MARTIN
6 | 7698 | BLAKE
7 | 7782 | CLARK
8 | 7839 | KING
9 | 7844 | TURNER
10 | 7900 | JAMES
11 | 7902 | FORD
12 | 7934 | MILLER
(12 rows)
