查找重复数据sql

多个字段：

select * from froute_cp_table a
where (a.arrivecity,a.departcity,a.flightrouteline) in?? (select arrivecity,departcity,flightrouteline from froute_cp_table group by arrivecity,departcity,flightrouteline? having count(*) > 1)