description of the students table:
sid_id number
start_date date
end_date date
which two function are valid on the start_date column?_________。
A.sum(start_date)
B.avg(start_date)
C.count(start_date)
D.avg(start_date,end_date)
E.min(start_date)
F.maximum(start_date)
------解决方案--------------------
C,E
正确
which two function are valid on the start_date column?_________。
A.sum(start_date) --日期不能这样求和,dateadd()
B.avg(start_date) --日期也不能这样算平匀
C.count(start_date)--可以
D.avg(start_date,end_date)--没有这种用法
E.min(start_date)--正确
F.maximum(start_date)--maximum错误，max