Are These Expressions Equal?

TechJack · **Joined:** Thu Aug 20, 2009 10:03 am **Posts:** 3

Hello there,
with the following Code i am trying to build a Criteria Query that should get me all the fitting attachmentHead Objects. Raw SQL should look Like this:

Code:

Select * from attachmentHeads Where maMailid = [arraycontent]

In my Project i tried something like this:

Code:

public IList getAttachmentHeads(IList mailsheads)
{
            ICriteria crit = session.CreateCriteria(typeof(attachmentHead));
            for (int i = 0; i < mailsheads.Count; i++ )
            {
                crit = crit.Add(Expression.Eq("maMailid", ((mailsHead)mailsheads[i].maMailid)));
            }
           return crit.List();
}

Instead of working properly it only returns an empty List.
What should I do?

Thx!

wolli · **Posted:** Fri Aug 21, 2009 2:01 am

crit = crit.Add(Expression.Eq("maMailid", ((mailsHead)mailsheads[i].maMailid)));

This statement creates "and". You have to either use Expression.Or(...) or Expression.PropertyIn(...):

Code:

ICriteria crit = session.CreateCriteria(typeof(attachmentHead));
List<int> ids = new Listt<int>(mailsheads.Count);
for (int i = 0; i < mailsheads.Count; i++ )
     ids.Add(((mailsHead)mailsheads[i].maMailid)));

return crit.Add(Expression.In("maMailid", ids ).List();

TechJack · **Joined:** Thu Aug 20, 2009 10:03 am **Posts:** 3

Danke ;)

TechJack · **Joined:** Thu Aug 20, 2009 10:03 am **Posts:** 3

I still have a second question, wich is too minimal to have an own Thread:
How do i downscale the result to one Column/Property?

Have a nice day ;)

wolli · **Posted:** Fri Aug 21, 2009 4:38 am

criteria.SetProjection(Projections.Property("...."))