Re: [Hibernate-devel] Is this type of query possible?

[Gavin_King/Cirrus%<CI...@ci...>]

> Basically, there is a parent table ("foo" in my example above) and
> there is list of attributes for a particular foo object
> (called "foo_attr") in my example above.  I want to find all Foo's
> where it have an attribute "attribute1" equal to "value1" and an
> attribute "attribute2" equal to "value2".
>
> So, is this something I will have to implement (and if so, are there
> suggestions on the syntax of the query), or does this already exist?

I *think* I understand what you are trying to do though I'm not sure
why you used a nested subselect so perhaps there is something I'm
missing.

If you were to map this as a (nested) one-to-many set of Attibutes, I
think you can express this as:

select foo
from foo in class Foo, att1 in foo.attributes, att2 in foo.attributes
where att1.name = 'attribute1' and att1.value = 'value1'
and att2.name='attribute2' and att2.value = 'value2'

(though the generated SQL here contains no subselects). What I would
love to be able to do would be to map this instead as a (nested) map
with String index + element and then express the query as:

from foo in class Foo
where foo.attributes['attribute1']='value1'
and foo.attributes['attribute2']='value2'

However, the [] indexing syntax is not implemented. The advantage of
this approach is we don't have to invent this whole new class called
Attribute to contain name/value pairs. If someone wants to implement
[], that would be wonderful - but it might be nontrivial.

Does that help?