oracle 表中有子父关系列则使用CONNECT BY PRIOR

查询名字为xx xxx的所有子数据

SELECT re.UUID
  FROM INF_xxx re
CONNECT BY PRIOR re.UUID = re.PARENT_UUID
 START WITH re.xxx_name in ('xxx', 'xx')

通过CONNECT BY生成序列

SQL> SELECT ROWNUM FROM DUAL CONNECT BY ROWNUM <= 10;
 
    ROWNUM
----------
         1
         2
         3
         4
         5
         6
         7
         8
         9
        10
 
10 rows selected

最近30天的日期统计

SELECT TO_CHAR(TO_DATE('2013-01-01', 'YYYY-MM-DD') + ROWNUM - 1,
               'YYYY-MM-DD') AS SYSTEMDATE
  FROM DUAL
CONNECT BY ROWNUM <= 30;

获得字符串的各个字符

SELECT SUBSTR('ORACLE',ROWNUM,1) FROM DUAL 
CONNECT BY ROWNUM=LENGTH('ORACLE')