select
states.state_id,
states.state_name,
cities.city_id,
cities.city_name,
cities.region_id
from states
inner join cities
on states.state_id=cities.state_id
where states.countrycode=”counttrycode“;
也可以使用别名：
如下：
select
s.state_id,
s.state_name,
c.city_id,
c.city_name,
c.region_id
from states s
inner join cities c
on s.state_id=c.state_id
where s.countrycode=”counttrycode“;
s 是states的别名， c是cities的别名。这样当名字很长时比较好用。