Question: Show the names of conductors that have conducted more than one orchestras.
Schema: create table orchestra (conductor_id varchar, PRIMARY KEY (conductor_id)); create table conductor (name varchar, conductor_id varchar, PRIMARY KEY (name))
SQL: select t1.name from conductor as t1 join orchestra as t2 on t1.conductor_id = t2.conductor_id group by t2.conductor_id having count(*) > 1