연령별 집계

SELECT [총   ] = count(age)
     , [10대] = count(case when age/10=1 then 1 end)
     , [20대] = count(case when age/10=2 then 1 end)
     , [30대] = count(case when age/10=3 then 1 end)
     , [40대] = count(case when age/10=4 then 1 end)
     , [50대] = count(case when age/10=5 then 1 end)
     , [60대] = count(case when age/10=6 then 1 end)
     , [70대] = count(case when age/10=7 then 1 end)
     , [80대] = count(case when age/10=8 then 1 end)
     , [90대] = count(case when age/10=9 then 1 end)
FROM TABLE