oracle查询不包含多个字符串方法

怎么做首先截取dev_id字段15位字符串，在根据字符串内容查询task_id字段不包含1和5的，并且去掉dev_id的重复数据？

select substr(dev_id, 1, 15) as dev_id
from your_table
where task_id not like '%1%'
  and task_id not like '%5%'  
group by substr(dev_id, 1, 15)
having count(substr(dev_id, 1, 15)) = 1