select t.*
from (select order.org_id
from order o
where o.org_id = 102528 order by o.id
) t
where rownum <= 1
如果order by o.id是主键,内查询先执行排序,在执行where,很慢
select t.*
from (select order.org_id
from order o
where o.org_id = 102528 order by o.id
) t
where rownum <= 1
如果order by o.id是主键,内查询先执行排序,在执行where,很慢