คงคล้ายๆ แบบนี้ครับ
select o.*, concat(p.pname,p.fname,' ',p.lname) as patient_name ,ar.relation_name ,ag.allergy_group_name,
asr.seiousness_name ,ars.result_name,sp.name as spclty_name
from opd_allergy o
left outer join patient p on p.hn = o.hn
left outer join allergy_group ag on ag.allergy_group_id = o.allergy_group_id
left outer join allergy_seriousness asr on asr.seriousness_id = o.seriousness_id
left outer join allergy_result ars on ars.allergy_result_id = o.allergy_result_id
left outer join allergy_relation ar on ar.allergy_relation_id = o.allergy_relation_id
left outer join spclty sp on sp.spclty = o.spclty