Specifying a datatype for foreign id fields

[mifri...@gmail.com]

Sometimes I would like to specify datatypes for foreign id fields. For example, all my id fields are 64 bit longs. But sometimes, I would like to have foreign id fields which are only 32 bit without changing the id fields itself for saving space. Using datatype=Integer doesn't work because this throws a messages about only possible on Integer types...

Yes, it is a bit dirty, but this would be the best solution for my specific problem ;-)