您的查询看起来还可以，但不会导致最大appid的记录集.

试试

your query looks okay but it will not result the record set of the maximum appid.

try

select *
from Appointment
where appID = (
select max(appID)
from Appointment
where patID='p00000001')

另外，希望patID列是varchar吗?

Also, hope the patID column is varchar ?