public IEnumerable<Column> GetColumnNotInRelationships()
{
try
{
var inRelations = this.GetColumnInRelationships();
var retval = new ColumnCollection(this.Root);
foreach (var c in this.GetColumns())
{
if (!inRelations.Contains(c))
retval.Add(c);
}
return retval.OrderBy(x => x.Name);
}
catch (Exception ex)
{
throw;
}
}