hibernate - Query failing unless I reorder the values in SELECT statement -

i'm trying hql query don't understand why query fails if don't reorder values in select statement

following query not work

query 1

@query("select uf.flight.arrivalairport.iatacode, uf.flight.flightstatus " +         "from userflight uf uf.flight.id=?1 , uf.user.id=?2") 

generated sql

select airport2_.iata_code col_0_0_,  flight1_.flight_status_id col_1_0_,  flightstat4_.id id1_6_,  flightstat4_.code code2_6_,  flightstat4_.description descript3_6_  user_flight userflight0_,  flight flight1_,  airport airport2_  inner join flight_status flightstat4_  on flight1_.flight_status_id=flightstat4_.id  userflight0_.flight_id=flight1_.id  , flight1_.arrival_airport_id=airport2_.id  , userflight0_.flight_id=?  , userflight0_.user_id=? 

exception

com.mysql.jdbc.exceptions.jdbc4.mysqlsyntaxerrorexception: unknown column 'flight1_.flight_status_id' in 'on clause'

if change query following (just reordering select values)

query 2

@query("select uf.flight.flightstatus, uf.flight.arrivalairport.iatacode " +         "from userflight uf uf.flight.id=?1 , uf.user.id=?2") 

generated sql

select flight1_.flight_status_id col_0_0_,  airport4_.iata_code col_1_0_,  flightstat2_.id id1_6_,  flightstat2_.code code2_6_,  flightstat2_.description descript3_6_  user_flight userflight0_,  flight flight1_  inner join flight_status flightstat2_  on flight1_.flight_status_id=flightstat2_.id,  airport airport4_  userflight0_.flight_id=flight1_.id  , flight1_.arrival_airport_id=airport4_.id  , userflight0_.flight_id=?  , userflight0_.user_id=?  

it works , results database.

can tell me why 1 of them working , other not?

note: flightstatus entity , not string value.

the error here:

in first query have:

... airport airport2_  inner join flight_status flightstat4_  on flight1_.flight_status_id=flightstat4_.id  ... 

so interpreter thinks want link airport2_ , flighstat4_, on clause isn't correct

instead, in second query, have:

... flight flight1_  inner join flight_status flightstat2_  on flight1_.flight_status_id=flightstat2_.id,  ... 

the on clause correct 2 tables flight1_ , flighstat2_

edit

when write:

select uf.flight.arrivalairport.iatacode, uf.flight.flightstatus 

the interpreter decomposes objects in order:

processes first field:

uf (user_flight) -> flight (flight) -> arrivalairport (airport) 

so processes second field:

uf (user_flight) -> flight (flight) 

these 2 objects present in tables, reuses them but, order of join defined have first layout (with error).

when change order of field, second field (of first query) has been processed first , old first second, have second lasyout without error.

i hope, i'm clean in explanation :)