I have this query :

ISQLQuery query = session.CreateSQLQuery("select * from tbl where someColumn=:someValue");

And I need to do the next :

query.SetInt32("someValue", null);

but I have Exception.

How can I set null to my parameter?

You can't ... if your column can contain NULL values and you map it to a value type, you have to use a nullable (Int32?).
Actually with most (if not all) databases "column = null" wouldn't work. If you want to compare with null, you have to use "column is null".

Ok, I know this and I use Nullable type.
but it doesn't helps me.
For ex:
int? someValue;
someValue = null;

and then I cannot use :
query.SetInt32("someValue", someValue);
Because the second parametr has type int, so
I can use only this -

query.SetInt32("someValue", someValue.Value);

and this is not resolve of my problem.

Sorry, wasn't clear from your post. Try

query.SetParameter("someValue", someValue);

thanks,
I'll try to use SetParameter.

SetParameter doesn't work with Nullable types.
Who knows other variants?

Thanks all.

I've done following:

int? val = ...;

if (val.HasValue
query.SetInt32("someValue", val.Value);
else
query.SetString("someValue", null);

Are you sure that you get the expected sql statement ? Does hibernate translate the null value to "somevalue is null" ? Afaik "somevalue = null" won't return anything ... maybe that depends on the DB, at least SQL server returns nothing at all ?