having 和where是否可同时使用？

Question

having和where同时使用的例子？

Answer 1

可以。example
select count(*), person_id
from per_all_people_f
where sysdate between effective_start_date and effective_end_date
group by person_id
having count(*) > 1

Answer 2

where用于前面的过滤，having用于后面groupby后的过滤，两者不冲突。完全可以同时使用。

Answer 3

当然可以。
where是在汇总之前进行筛选；
having 是在汇总之后进行筛选。