NHibernate QueryOver For Complex Model

Question

I have a domain object that I'm trying to use QueryOver on to search a property of a sub, sub collection and I'm not sure how to approach this using QueryOver.

The POCOs look like this:

public class Case {
    public virtual string CaseId { get; set; }
    public virtual string CaseNumber { get; set; }
    public virtual IList<Request> Requests { get; set; }
}

It has a collection of Requests:

public class Request {
    public virtual int RequestId { get; set; }
    public virtual IList<RequestIndividual> RequestIndividuals { get; set; }
}

Which has a collection of Request Individuals:

public class RequestIndividual {
    public virtual int RequestId { get; set; }
    public virtual string IndividualType { get; set; }
    public virtual string FirstName { get; set; }
    public virtual string MiddleName { get; set; }
    public virtual string LastName { get; set; }
    public virtual string Company { get; set; }
}

Using NHibernate's QueryOver, I'm able to Join to get to my Request collection, but how would I get into the RequestIndividual collection to find one by FirstName?

var query = _session.QueryOver<Case>();

if (!string.IsNullOrEmpty(finder.IndividualFirstName))
{
    query.JoinAlias(x => x.Requests, () => reuestsAlias, JoinType.LeftOuterJoin)
    // This is where I'm stumped. How to query the request for the individuals and find the first name?
}

UPDATE : The complete query looks like this and works, thanks to, xanatos:

query.JoinAlias(x => x.Requests, () => reuestsAlias, JoinType.LeftOuterJoin)
                    .JoinAlias(() => reuestsAlias.RequestIndividuals, () => requestIndividiualAlias)
                    .Where(() => requestIndividiualAlias.FirstName == finder.IndividualFirstName);

Answer 1

From here

query.JoinAlias(x => x.Requests, () => reuestsAlias, JoinType.LeftOuterJoin)

You do this:

RequestIndividual requestIndividualAlias;

query.JoinAlias(() => reuestsAlias.RequestIndividuals, () => requestIndividualAlias);

There is a whole "set" of QueryOver methods that instead of being x => x. are () => alias. . I normally ALWAYS prefer to use them (and to use JoinAlias instead of JoinQueryOver ) because it's explicit what you are speaking of (with JoinQueryOver you have to think... x => x. , but x what is?