oracle 两个sql带有order by的使用union/union all的时候报错 'ORA-00933:sql命令未正确结束' 处理办法

错误语句：select id,name from s1 order by stime union all select id,name from s2 order by stime 

报错原因：oracle 搜索到order by后认为整个select语句就该结束了但是后面还有union all所以数据库无法解析，导致报错

处理办法：with a1 as (select id,name from s1 order by stime) , a2 as (select id,name from s2 order by stime)  select * from a1 union all select * from a2