Hello,

I'm new to Nhibernate and am attempting to use it to implement a 'search form'. I'm following section 8.5.2 in "NHibernate in action" - Dynamic Queries.
My search form includes fields from more than one domain object (ie. tables). In my case, the second domain object is a property of the first. I don't know if this is significant.

So, i'm creating example objects based on an instance of the actual objects and adding these to the criteria.

//Create Example object based on instance x.
Example exampleX = Example.Create(instanceX).IgnoreCase().EnableLike(MatchMode.Anywhere);

//Create Criteria object of type ClassX.
ICriteria criteria = session.CreateCriteria(typeof(ClassX));

//Add our Example to the criteria object.
criteria.Add(exampleX);

Example exampleY = Example.Create(instanceX.instanceY)
.EnableLike(MatchMode.Exact);

//Add to existing criteria.
criteria.CreateCriteria("XYJoin").Add(exampleY);

//List method returns objects of specified type.
criteria.List(xList);

This works ok while i supply values for properties in x and y, but returns the wrong results when i only supply values in the y object (ie. the sub-object).

I may be making an incorrect assumption about the way "query by example" works, but shouldn't i be able to return objects which contain a match in the sub-criteria?

Any help appreciated.

Chris.

So,

I'm still trying to find a definitive solution to this, but have got a step further by using "CreateAlias".

e.g.
criteria.CreateAlias("ClassY", "classY");
criteria.Add(Expression.Eq("classY.Id", "ClassY"));

However, I don't want the effort of creating criterion for each of the properties of the objects (and sub-objects, and their sub-objects).

Is there a way to use Query By Example in conjunction with the alias?

Any ideas?