formula attribute in hbm

bks · **Posted:** Sat Jul 21, 2007 5:13 am

I used this attribute in my program but no reaction in table .
but it excuate without exception and error

for Eg
<property name='total' formula="mark1+mark2" />

karlchu · **Posted:** Sat Jul 21, 2007 11:12 am

A property that is mapped to a formula is read-only.

bks · **Posted:** Tue Jul 24, 2007 6:48 am

that colum is not in my table

how can i solve this..

please explain briefly..

i am new biginner in hibernate.

karlchu · **Posted:** Tue Jul 24, 2007 10:17 am

For example, you mapped a property "LineTotal" to be "Quantity * ItemPrice". When NHibernate does a select it does this:

Code:

SELECT Quantity * ItemPrice AS LineTotal FROM ...

What do you suppose NHibernate should write back to the database when you do a save? Therefore, property mapped with a formula is read-only. Hope this clear things up.