oracle with语句

[align=center][size=xx-large][color=violet]oracle with语句[/color][/size][/align]
下面是一个示例语句：

WITH a AS (SELECT
*
FROM scott.emp),
          b AS (SELECT
*
FROM scott.dept)
  SELECT a.deptno, b.dname, a.empno, a.ename
    FROM a, b
      WHERE a.deptno = b.deptno
        ORDER
BY a.deptno, a.empno;

使用WITH子句有时可以简化FROM子句的复杂性。