What is the id and detail of the vehicle used in lessons for most of the times?
create table lessons (vehicle_id varchar, PRIMARY KEY (vehicle_id)); create table vehicles (vehicle_id varchar, vehicle_details varchar, PRIMARY KEY (vehicle_id))
select t1.vehicle_id, t1.vehicle_details from vehicles as t1 join lessons as t2 on t1.vehicle_id = t2.vehicle_id group by t1.vehicle_id order by count(*) desc limit 1