count the number of times that patient 9566 during the previous day has had an gastric oral gastric output.
select count(*) from outputevents where outputevents.icustay_id in ( select icustays.icustay_id from icustays where icustays.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 9566 ) ) and outputevents.itemid in ( select d_items.itemid from d_items where d_items.label = 'gastric oral gastric' and d_items.linksto = 'outputevents' ) and datetime(outputevents.charttime,'start of day') = datetime(current_time,'start of day','-1 day')