I am fairly certain that this is something simple, but every example I have tried is failing. I want to query a table like this
ID   Part_Type   Station_Typ         
        select id, part_type, station_type 
from myTable t1
where exists (select 1 from myTable t2
              where t1.part_type = t2.part_type
                  and t1.station_type = t2.station_type
                  and t1.id <> t2.id)
                                                                        I think a self-join will work for you:
SELECT * FROM table t1 
INNER JOIN table t2 ON t1.Part_Type = t2.Part_Type 
  AND t1.Station_Type = t2.Station_Type
  AND t1.Id <> t2.Id
                                                                        You can use the following:
select t1.id, t1.part_type, t1.station_type
from yourtable t1
where exists (select part_type, station_type
              from yourtable t2
              where t1.part_type = t2.part_type
                and t1.station_type = t2.station_type
              group by part_type, station_type
              having count(id) > 1)
See SQL Fiddle with Demo