example:
select sum(case when age<=6 then 1 else 0 END) as '0-6', sum(case when age>=7 and age<=18 then 1 else 0 END) as '7-18', sum(case when age>=19 and age<=25 then 1 else 0 END) as '19-25', sum(case when age>=26 and age<=30 then 1 else 0 END) as '26-30', sum(case when age>=31 and age<=35 then 1 else 0 END) as '31-35', sum(case when age>=36 and age<=40 then 1 else 0 END) as '36-40', sum(case when age>=41 and age<=45 then 1 else 0 END) as '41-45', sum(case when age>=46 and age<=50 then 1 else 0 END) as '46-50', sum(case when age>=51 and age<=55 then 1 else 0 END) as '51-55', sum(case when age>=56 and age<=60 then 1 else 0 END) as '56-60', sum(case when age>=61 and age<=65 then 1 else 0 END) as '61-65', sum(case when age>=66 and age<=70 then 1 else 0 END) as '66-70', sum(case when age>=71 and age<=75 then 1 else 0 END) as '71-75', sum(case when age>=76 and age<=80 then 1 else 0 END) as '76-80', sum(case when age>=81 then 1 else 0 END) as '≧81' from ( select age from his_sign hs ) age