gp converts seconds into hours, minutes and seconds
case
when col >= 3600 then
case when col%3600 > 60 then col/3600||'h'||col%3600/60||'m'||col%3600/60||'s'
else col/3600||'h'||col%3600/60||'s'
end
when col >= 60 and col < 3600 then col/60||'m'||col%60||'s'
else col||'s'
end as col