Does Hibernate support subquery (subselect) in "FROM" clause

greenfield_sg · **Joined:** Fri Jun 12, 2009 5:51 am **Posts:** 3

Hi,

I've searched around for the answer but haven't found any confirmation yet.

One said it may occur only in 'select' & 'where' clauses. https://forum.hibernate.org/viewtopic.php?f=1&t=984148&start=0

If you used it before, please let me know. Thanks!

parag.gajbhiye · **Posted:** Fri Jun 12, 2009 9:11 am

Hi greenfield_sg ,,,,

U can refer the book----> Professional Hibernate page no:-202 for more information

Hql querry may be like this:-

from Group as group where size(group.stories) > (
select avg(size(storygroup.stories)) from Group storygroup)

bye.tc

fge · **Joined:** Mon Jun 01, 2009 5:39 am **Posts:** 34

HQL still will NOT support subselect in the from clause.

Among other things it will not support is aliases to computed columns in the select clause, which quite fall under the same category. You cannot do:

Code:

select f(c1, c2, c3) as c from thetable where [some condition on c]

greenfield_sg · **Joined:** Fri Jun 12, 2009 5:51 am **Posts:** 3

Thanks fge & parag.gajbhiye...

My query is like this:
------
select A.col1, A.col2, resultList.col1
from table1 as A
outer join ( (select B from table2 as B where [condition]) as resultList )
------

In the hibernate mapping, table B contains A's pk, hence they both can join.
I tried in SQL, it worked (i need to write 1 more line, to specify join on which columns).
But i tried in HQL, it returned error.