select vs.vstdate,vs.hn,dt.vn ,dt.dt_list,vs.pdx,vs.dx0,icd10 from dt_list dt
left outer join vn_stat vs on vs.vn = dt.vn and vs.vstdate between'2013-01-01' and '2013-03-31'
left outer join ovstdiag ov on ov.vn = vs.vn
where ov.icd10 >="e100" and ov.icd10 <= "e149" or ov.icd10 = "i10" and dt.dt_list <> " "
group by dt.vn
order by vs.hn ,vs.vstdate
ลองนำไปรันดูนะครับ