NHibernate many to many backward query - nhibernate

Question

This is a question asked with an ignorance of thew subject matter, but i have searche dlong and hard so i hope this will not be too painful.
I'm using nhibernate for a many to many query.
My objects map (not my design, not getting changed any time soon):
Computer (id, name, etc...) -> (mapping table ) -> Config ( id, key, value )
One computer may have many configs, any config may belong to multiple computers. i can read a computer out fine and the list(bag) member is populated fine.
I then want to find a computer that has numerous configs.
E.g. all computers that have:
OS : Windows
CPU : 2GHz
etc.
Any assistance on how I could put this into a criteria query would be greatly appreciated. I've done some of the basics but wrapping my head around this is proving hard work.
Cheers for any assistance,
Rob.

Answer 1

If the parameters are always the same, use a query like the following:
var computers = session.CreateQuery(
#"select c
from Computer c
inner join c.Configurations as osconfig
inner join c.Configurations as cpuconfig
where
osconfig.Name = 'OS'
and osconfig.Value = :os
and cpuconfig.Name = 'CPU'
and cpuconfig.Value = :cpu")
.SetString("os", "Windows")
.SetString("cpu", "2GHz")
.List<Computer>();
If you mapped it as a map, you can even do something like this:
var computers = session.CreateQuery(
#"select c
from Computer c
where
c.Configurations['OS'] = :os
and c.Configurations['CPU'] = :cpu")
.SetString("os", "Windows")
.SetString("cpu", "2GHz")
.List<Computer>();
If the parameters are always different, use criteria to add them dynamically.