what is the minimum hospital cost involving a drug that is called 0.9% sodium chloride (mini bag plus)?
select min(t1.c1) from ( select sum(cost.cost) as c1 from cost where cost.hadm_id in ( select prescriptions.hadm_id from prescriptions where prescriptions.drug = '0.9% sodium chloride (mini bag plus)' ) group by cost.hadm_id ) as t1