Mysql语句：
select count(a.site_id) ,
(select attr_value from site1_attr where site_id = a.site_id and attr_id = '01') as d1 from site1 a
where 1=1 and site_id in (select site_id from site1_attr where attr_id = '02' and attr_value ='上海')
group by d1 having count(a.site_id) >=1
Oracle语句：
select count(a.site_id),b.attr_value from site1 a ,site1_attr b where a.site_id = b.site_id and
a.site_id in (select site_id from site1_attr where attr_id = '02' and attr_value = '上海') and
b.attr_value in (select attr_value from site1_attr where attr_id = '01')
group by b.attr_value
having count(a.site_id) >= 1;