NHibernate.QueryException: expecting ‘elements’ or ‘indices’ after…

Yes, it’s true. I have two lovers. Well more like I’m stuck with NHibernate due to some kind of stupid forced marriage and the other is my somewhat quirky but ultimately young and hot mistress Entity Framework. And now that I’ve admitted to such an atrocity you are about to run screaming, I’ll get on with what the hell this means.

So I ran across this the other day and well I’m sure a smart person would immediately understand what it means, but that smart person doesn’t write for this blog. You’re stuck with me. So after some staring at the screen and praying to whatever god I just learned about on wikipedia, I figured it out. Now I can’t promise this is the only reason to get this error, but this is the answer I have.

Say you have a user and with that user you have a list of events. Now it should be obvious that there is an event class, an event table, and user table. Simple enough. Now in hql, it would look something like this:

       User user
       user.Events event
       user.Events.Status = SomeStatusEnum.SomeValue

And yes I realize that it doesn’t need to be a left join, but just roll with me on this because I don’t feel like making a better example. So if you look close enough at the query you should see something wrong… Why would I join the objects and then refer to the event status through the user?

       user.Events.Status = SomeStatusEnum.SomeValue

Because I’m a tool. Yeah turns out that, to me, crytic message is really saying “Use the joined object alias you f-ing tool.” In other words:

       events.Status = SomeStatusEnum.SomeValue

And boom. No more error.