Cursor that gets names of sailors who’ve reserved a red boat, in alphabetical order

Note that it is illegal to replace S.sname by, say, S.sid in the ORDER BY clause! (Why?)

Can we add S.sid to the SELECT clause and replace S.sname by S.sid in the ORDER BY clause?

SELECT S.sname

FROM Sailors S, Boats B, Reserves R

WHERE S.sid=R.sid AND R.bid=B.bid AND B.color=‘red’

ORDER BY S.sname;

FETCH 5 IN sinfo;

Note that it is illegal to replace S.sname by, say, S.sid in the ORDER BY clause! (Why?)