Linq to nhibernate sql 1 = 1 equivalent - linq

Question

I am trying to do a search with LINQ to NHibernate.
I have this code:
from d in rep.QueryAll<Document>()
where
d.Plata != null && d.Contractant != null && d.Stadiu == StadiuDocument.Polita
&& (d.NrPolita.Contains(query) ||
d.Contractant.CodUnic.Contains(query) ||
d.Contractant.Denumire.Contains(query) ||
d.Plata.IdTranzactie.Contains(query)) &&
((TipPolita != null) ? (d.Tip == (TipProdus)TipPolita) : (1 == 1)) &&
((StareDocument != null) ? (d.Stare == (StareDocument)StareDocument) : (1 == 1))
select new
{
The problem is that I have some select inputs that have general values. Something like this:
<select id="tippolita" >
<option value = "-1">Any value</option>
<option value = "1">Value 1</option>
<option value = "2">Value 2</option>
<option value = "3">Value 3</option>
</select>
So when "Any value" is selected the where statement should be true like I wrote here:
((TipPolita != null) ? (d.Tip == (TipProdus)TipPolita) : (1 == 1)) &&
((StareDocument != null) ? (d.Stare == (StareDocument)StareDocument) : (1 == 1))
This is almost the same as what I would write in SQL.
An error occurs inside the Nhibernate source code at line 33 in the file "Linq\NHLinqExpression.cs"
_expression = PartialEvaluatingExpressionTreeVisitor.EvaluateIndependentSubtrees(expression);
This error actually comes from the re-linq library.
One obvious workaround is to just write 3 if statements and put the appropriate LINQ queries in each of them but that means writing a lot more code.
Is there any way to make this kind of query work without copy-pasting the entire query and modifying just a little of it?
P.S.
This is the inner exception:
InnerException: System.NullReferenceException
Message=Object reference not set to an instance of an object.
Source=Anonymously Hosted DynamicMethods Assembly
StackTrace:
at lambda_method(Closure
)

Answer 1

I would rewrite this:
((TipPolita != null) ? (d.Tip == (TipProdus)TipPolita) : (1 == 1)) &&
((StareDocument != null) ? (d.Stare == (StareDocument)StareDocument) : (1 == 1))
as
(TipPolita == null || d.Tip == (TipProdus)TipPolita) &&
(StareDocument == null || d.Stare == (StareDocument)StareDocument)
I don't know whether it'll work in NHibernate or not, but it's more idiomatic C# at least, so I would expect that it's more likely to be supported.
As an alternative, you could just replace "1 == 1" with "true".

Answer 2

Well, figured out how to do this the proper way
var date = rep.QueryAll<Document>().Where(d => d.Plata != null && d.Contractant != null && d.Stadiu == StadiuDocument.Polita);
if (!string.IsNullOrEmpty(query))
date = date.Where(d => (d.NrPolita.Contains(query) ||
d.Contractant.CodUnic.Contains(query) ||
d.Contractant.Denumire.Contains(query)));
I just move the ifs into the code and build the query(or rather the IQueryable) bit by bit