Nhibernate ICriteria - Check property value length - nhibernate

Question

I'm trying to return all entities where a given property is not empty.
The problem is IsNotEmpty() only applies to collections. Below is the general approach I've taken so far, it obviously doesn't work.
ICriteria lvCriteria = NHibernateHelper.GetCurrentSession()
.CreateCriteria(typeof(FunctionCall))
.SetMaxResults(100)
.AddOrder(Order.Desc("LogId"));
if (pvMsg.HasValue)
{
lvCriteria.Add(Restrictions.IsNotNull("Msg"))
.Add(Restrictions.IsNotEmpty("Msg"));
}
Any suggestions? Is it possible to achieve this result by checking the property value's length? Thank you!

Answer 1

Finally, I discovered the combination I was looking for!
lvCriteria.Add(Restrictions.Not(Expression.Eq("Msg", string.Empty)));
This combination of Restrictions and Expression works as expected; narrowing out all empty strings. I do not know why I could not achieve these results earlier even with:
lvCriteria.Add(Restrictions.Not(Restrictions.Eq("Msg", string.Empty)));
Thank you to all who tried.

Answer 2

I believe you're looking for:
.Add(Expression.IsNotEmpty("PropertyName"));
and
.Add(Expression.IsNotNull("PropertyName"));

Answer 3

Below are my mapping and class definition:
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" auto-import="true" assembly="Domain" namespace="Assembly.Domain">
<class name="Assembly.Domain.FunctionCall, Domain" lazy="false" table="FunctionCallLog">
<id name="LogId" column="LogId">
<generator class="native" />
</id>
<property name="LogTime" column="LogTime" />
<property name="Username" column="Username" />
<property name="CallerIp" column="CallerIp" />
<property name="FunctionName" column="FunctionName" />
<property name="Parameters" column="Parameters" />
<property name="Msg" column="Msg" />
<property name="FileName" column="FileName" />
<property name="TimeSpan" column="TimeSpan" />
</class>
</hibernate-mapping>
using System;
namespace Assembly.Domain
{
public class FunctionCall
{
public int LogId { get; set; }
public DateTime LogTime { get; set; }
public string Username { get; set; }
public string CallerIp { get; set; }
public string FunctionName { get; set; }
public string Parameters { get; set; }
public string Msg { get; set; }
public string FileName { get; set; }
public int TimeSpan { get; set; }
}
}

Answer 4

Try this:
ICriteria lvCriteria = NHibernateHelper.GetCurrentSession()
.CreateCriteria(typeof(FunctionCall))
.SetMaxResults(100)
.AddOrder(Order.Desc("LogId"));
if (pvMsg.HasValue)
{
lvCriteria.Add(Restrictions.IsNotNull("Msg"))
.Add(Restrictions.Not(Restrictions.Eq("Msg", ""));
}
There may be a more compact way of expressing this.