CODEWITHSUNDEEP
c#linqnhibernatelinq-to-nhibernate
user610217
user610217

Reputation:

Linq to NHibernate: how to get a list of child objects without having the lists nested

I have a Linq to NHibernate query as follows:

var profile = 
    from UserProfile up in _Session.Query<UserProfile>()
        .Fetch(x=>x.Messages)
    where up.UserName == userName
    select up.Messages;

this returns an IQueryable<IList<UserMessage>> which I then have to run a SelectMany() on. I'd prefer if I could just return an IQueryable<UserMessage> object instead, especially as the query will never return more than one user profile. Can this be done, or am I stuck with the extra step?

Upvotes: 2

Views: 833

Answers (2)

nemesv
nemesv

Reputation: 139778

If you map the other side of the navigation e.g have a UserProfile property on the UserMessage class, your can start from UserMessage:

var messages = 
    from UserMessage um in _Session.Query<UserMessage>()
    where um.UserProfile.UserName == userName
    select um;

Otherwise you need to use SelectMany() to get a flattened out list.

Upvotes: 1

ChaseMedallion
ChaseMedallion

Reputation: 21764

Could you query the messages table directly and use the reverse association?

IQueryable<Message> messages = ...;
var filtered = from m in messages
    where m.UserProfile.UserName == userName
    select m;

Also, if you're willing to forgo query syntax you could make this shorter with:

var profile = _Session.Query<UserProfile>()
    .Where(up => up.UserName == userName)
    .SelectMany(up => up.Messages);

Upvotes: 1

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