操作service表，查询unix服务器在哪几天的开户数多于1个，下列sql语句正确的是：( )
select unix_host,to_char(create_date,'yyyymmdd') create_date, count(os_username) cnt
from service where count(os_username) > 1
group by unix_host,to_char(create_date,'yyyymmdd');
select unix_host,to_char(create_date,'yyyymmdd') create_date, sum(os_username) cnt
from service having sum(os_username) > 1
group by unix_host,to_char(create_date,'yyyymmdd');
select unix_host,to_char(create_date,'yyyymmdd') create_date, count(os_username) cnt
from service
group by unix_host,to_char(create_date,'yyyymmdd')
having count(os_username) > 1;
select unix_host,to_char(create_date,'yyyymmdd') create_date, count(os_username) cnt
from service
group by unix_host,to_char(create_date,'yyyymmdd')
where count(os_username) > 1;
