Need help optimizing a NHibernate criteria query that uses Restrictions.In(..)
- by Chris F
I'm trying to figure out if there's a way I can do the following strictly using Criteria and DetachedCriteria via a subquery or some other way that is more optimal. NameGuidDto is nothing more than a lightweight object that has string and Guid properties.
public IList<NameGuidDto> GetByManager(Employee manager)
{
// First, grab all of the Customers where the employee is a backup manager.
// Access customers that are primarily managed via manager.ManagedCustomers.
// I need this list to pass to Restrictions.In(..) below, but can I do it better?
Guid[] customerIds = new Guid[manager.BackedCustomers.Count];
int count = 0;
foreach (Customer customer in manager.BackedCustomers)
{
customerIds[count++] = customer.Id;
}
ICriteria criteria = Session.CreateCriteria(typeof(Customer))
.Add(Restrictions.Disjunction()
.Add(Restrictions.Eq("Manager", manager))
.Add(Restrictions.In("Id", customerIds)))
.SetProjection(Projections.ProjectionList()
.Add(Projections.Property("Name"), "Name")
.Add(Projections.Property("Id"), "Guid"))
// Transform results to NameGuidDto
criteria.SetResultTransformer(Transformers.AliasToBean(typeof(NameGuidDto)));
return criteria.List<NameGuidDto>();
}
