Hibernate mapping option proposal

zubairov · **Posted:** Fri Apr 02, 2004 2:39 am

Hi All
I guess it's quite often to store child Sets or Bags of parent entity in the distinct database table. So, I like Hibernate because its really that I need :) so I can get size of the array without initialization of that array. But if Hibernate provides me with feathre to map a field of the object to SQL formula, so I can map a property Parent#childrensCount to "select count(*) from CHILDREN where PARENT_ID={id}" it would be nice either.

gavin · **Posted:** Fri Apr 02, 2004 3:24 am

This is possible!

zubairov · **Posted:** Sat Apr 03, 2004 3:59 am

Yes, but it require me to write a filter execution inside getChildrenCount method, but I'm talking about how nice it could be if it were already done by Hibernate, so the field childrenCount mapped not to database column but to query. Or I missed something in the docs?

anthony · **Posted:** Sat Apr 03, 2004 4:29 am

http://forum.hibernate.org/viewtopic.php?t=929568

it may help

gavin · **Posted:** Sat Apr 03, 2004 8:39 pm

Exactly.

Code:

<property name="childCount"
    type="integer" 
    formula="( select count(*) from Child c where c.parent = id )"/>