How to get the hour difference between 2 datetimestamp on derby db?

I have a sql question on derby database:

Select a.name, a.starttime, a.endtime
From a

How can I add to the above sql statement such that I can get the difference in hours between the start time and end time? (I only know that for mysql there is a DATEDIFF function, but I am not sure about what f开发者_Go百科unction should I use for derby db)

Thanks.

---

In Derby there is a TIMESTAMPDIFF:

for instance:

select {fn timestampdiff(SQL_TSI_FRAC_SECOND, startdate, enddate)} as diff