compute the number of times patient 14671 has been prescribed 0.9% sodium chloride (mini bag plus) during the current hospital visit.
select count(*) from prescriptions where prescriptions.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 14671 and admissions.dischtime is null ) and prescriptions.drug = '0.9% sodium chloride (mini bag plus)'