生成1-100的数字：select rownum from dual connect by rownum<=100
生成10-100的数字：select rownum+(10-1) from dual connect by rownum<=100-(10-1)
生成100以内的基数：select rownum*2-1 from dual connect by rownum<=50
生成100以内的偶数：select rownum*2 from dual connect by rownum<=50
生成100个随机数：Select Dbms_Random.random From dual connect by rownum<=100
