Nhibernate QueryOver by Enum Flags - nhibernate

Question

I have a query by QueryOver :
public IList<Person> SearchTest(PersonEnumType type)
{
var q = SessionInstance.QueryOver<Person>();
q = q.Where(x => (x.PersonEnumType & type) == type);
return q.List<Person>();
}
and PersonEnumType is a Enum flags :
[Flags]
public enum PersonEnumType
{
Employee1 = 1,
Employee2 = 2,
Employee3 = 4
}
This throws Could not determine member from (Convert(x.PersonEnumType) & Convert(value(NHibernate.Repository.PersonRepositoryNh+<>c__DisplayClass2).type))
Of course this works in Nhibernate.Linq.
Why?

Answer 1

if you've mapped your property properly in your mapping file:
<property name="PersonEnumType" type="MyApp.PersonEnumType, MyApp">
<column name="Person" default="1" />
</property>
You can achieve what you're looking for using filters.
I don't know if this is the only solution but, here it goes:
You can create a filter definition:
<filter-def name="PersonEnumTypeFilter">
<filter-param name="personType" type="MyApp.PersonEnumType, MyApp"/>
</filter-def>
and implement it in your class mapping:
<filter name="PersonEnumTypeFilter" condition="(:personType & PersonEnumType) = PersonEnumType"/>
Now you can switch on your filter:
public IList<Person> SearchTest(PersonEnumType type)
{
SessionInstance.EnableFilter("PersonEnumTypeFilter").SetParameter("personType", type);
var q = SessionInstance.Query<Person>();
return q.ToList<Person>();
}
You can read more about filters here.