# alap
select *
from diak, alvas, naptar
where diak.id = alvas.diakid 
and alvas.datum = naptar.datum ;

select *
from diak 
	join alvas on diak.id = alvas.diakid 
	join  naptar on alvas.datum = naptar.datum ;

select nev
from diak 
where fiu = 0 
order by nev;

select count(*)
from naptar
where melynap = 6 or melynap = 7;

select count(*)
from naptar
where melynap in (6,7);

select count(*)
from naptar
where melynap between 6 and 7;

#4
select *
from naptar 
where melynap  = 2
order by datum 
limit 1,1;

#5
select concat(diak.nev,": ", time(alvas.lefekves))
from diak 
	join alvas on diak.id = alvas.diakid 
where month(diak.szuldatum) = month(alvas.datum)
and day(diak.szuldatum) = day(alvas.datum);