Not lazy=false and not left join fecth, but depth feature

rocket · **Posted:** Thu Jul 08, 2004 5:51 pm

Hi all,
I'm using Hibernate and all features is very good.
However, in some cases I need to load an object with yours collections. In these cases the Hibernate have the lazy and fetch features.
But, I need this behavior in some cases.
So, it would be interesting an depth keyword in HQL.
Thus, it would be possible create these queries:

Code:

"from Group g left join fecth depth 3 u.groups"
"from Group g left join fecth depth 2 u.groups g1 left join fecth depth 5 g1.groups"
"from Group g left join fetch depth * u.groups"

This queries returns, respectively:
The group and yours 3 superior groups.
The group and yours 2 superiors groups and, for each of these groups, yours 5 superiors groups.
The group and all hierarchy of superior groups.

PS> Considering that a group have an auto-relationship, and the lazy attribute equals true.

Well, its my sugestion for Hibernate team.

christian · **Posted:** Thu Jul 08, 2004 5:54 pm

This is not possible with Hibernate, in fact, it is not even possible with SQL. You have to use vendor-specific extensions, such as "CONNECT BY" in Oracle or "SELECT RECURSIVE" in DB2. You may execute these queries with session.createSqlQuery().