Question: Find the busiest destination airport that runs most number of routes in China.
Schema: create table routes (dst_apid varchar, PRIMARY KEY (dst_apid)); create table airports (name varchar, apid varchar, country varchar, PRIMARY KEY (name))
SQL: select t1.name from airports as t1 join routes as t2 on t1.apid = t2.dst_apid where t1.country = 'china' group by t1.name order by count(*) desc limit 1