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 reCONNECT 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 DUALCONNECT 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')