Why MIN/MAX functions work only on numbers?

[paszti]

Hi all!

I use PostgreSQL and JBoss 3.2.3.

I'd like to perform a JBoss ql select that search the maximum value of a timestamp typed column.

This fails because I get a find exception reporting me that the current timestamp value is a "Bad double".
Do the newly introduced aggregate functions work only on number parameters?

Another solution would be if I could create to each timestamp cmp field a pair containing the same value in long type.

I don't want that these long fields become persistent fields, but I'd like that these fields can be used in a jboss ql select.

Can I create these kind of fields?

I saw that XDoclet has a @jboss.not-persisted-field tag, but there's no documentation concerning the purpose of this tag.

Could anyone know the solution?

Tibor

[aloubyansky]

That's true. The query should be compiled correctly. The problem occurs at reading the result, right? You can submit a bug report for this case. (It should work in HEAD).

Only, CMP fields can be used in queries.