Question

Have a scenario where I need to only select a single/few columns from an entity, but multiple children in a query.
I have been trying with projections but getting an error on the collections property. This is such a normal situation, yet cannot find info on projecting collections – only properties.

Customer customerAlias = null;
Order orderAlias = null;
 var list = _session.QueryOver<Customer>(() => customerAlias)
                    .JoinAlias(x => x.Orders, () => orderAlias, JoinType.LeftOuterJoin)
                    .Select(
                       Projections.Property(() => customerAlias.Name),
                       Projections.Property(() => customerAlias.Orders))//this is the issue
                   .List<object>();

Error returned is:

System.IndexOutOfRangeException : Index was outside the bounds of the array

Answer 1

Cannot be done in NH 3.3. https://nhibernate.jira.com/browse/NH-3176