ผม มือใหม่นะครับ ลองดูนะครับ
select count(vn),icd10 from ovstdiag
where vstdate between '2012-05-01' and '2012-05-31'
and icd10 in ('Z340','Z341','Z342','Z343','Z344','Z345','Z346',
'Z347','Z348','Z350','Z351','Z352','Z353','Z354','Z355','Z356','Z357','Z358','Z359')
group by icd10 limit 100