I am using a query which has a parameter of orderList and uses it like:
select orderLine from OrderLine orderLine
where orderLine.order in (:orderList)

The orderList is the result of a comlicated algoritm using other queries.
Sometimes this orderList is empty, in which case I would except that there aren't any orderLines which are in the given orderList.
Instead, Hibernate throws an exception: "unexpected end of subtree",
because the list is empty.
Is this the way it was intended? Should I escape specifically an emtpy orderList?

Using hibernate 3.1.1 with hibernate annotations beta8.

you should escape it to avoid an unnecessary DB roundtrip.
Actually some DB do not support .. in () <- empty element

HSQLDB doesn't support it.
I 'll escape it, thanks for the info.