Hi, I'm having some trouble querying using properties of associated objects.

To boil down to an easy example, let's say I've got a BlogPost class, and a User class. Each BlogPost belongs to a User.

BlogPost is mapped to User using a many-to-one relationship. However, I can't seem to retrieve ILists of BlogPosts belonging to a given User's username property.

I'd like to grab the list like this:



Is it in fact considered legal to do that "User.UserName" in a situation like this?

Here's the retrieval method:




I've also tried it using HQL. This works:



Any idea whether it's possible using the Criteria interface?

Have you tried "this.User.Username" instead?

Otherwise, you could probably insert .createAlias("User", "u") and then pass in "u.Username" instead of "User.Username".

Also, shouldn't your if statements be stated if (order.equals("ASC"))? I don't think you're going to order anything otherwise.

No, == works like Equals for strings in C#.

Hi,

Interesting idea with using an alias, I'll try it out but may not get it working until Monday (my "Hibernate in Action" is at work currently).

Will report back if it looks like it'll work, thanks for the reply.

In response to the question about "==", it works fine. I've actually written up a couple of classes that deal with almost all of the data requests for any type in a web app, so basically I can do up a pseudo-Ruby on Rails style query using this sort of syntax (let's say Article is a persistent page in a web site):


// get article with id of 5
Article article = new Article().Get(5);

or

// get article where the title is "Foo"
Article article = new Article().Get("Title", (object)"foo");

or

// list all active articles
IList articles = new Article().List("Active", (object)true);

The chunk of code I quoted in the first post is part of this class; I'm really enjoying web apps a lot more since integrating it into the stuff we're doing, it makes data work so much easier.

Would be nice if I could figure out how to make the retrieval calls into static methods, like:

Article article = Article.Get(5);

But currently I can't get this to work...