Lack of NHibernate HQL support for question mark character in column name

If you’re faced with a database that contains reserved characters in some of its column names, NHibernate allows you to escape a column name in the mapping file by wrapping the column name in backticks, for example:

<class name="Foo">
   <property name="Bar" column="`Bar?`" />
</class>

This convention is used by NHibernate to generate SQL with the column name wrapped appropriately (e.g. [] for SQL Server). This works as intended for ICriteria queries and for HQL queries returning tuples in the following form:

session.CreateQuery("select Bar from Foo").List();

For SQL Server this results in the following SQL:

select foo0_.[Bar?] as col_0_0_
from Foo foo0_

The problem occurs if you use the entity selection form of the HQL query in conjunction with the generic List method:

session.CreateQuery("select foo from Foo foo").List<Foo>();

In this scenario, when constructing the SQL statement NHibernate interprets the question mark as a position parameter placeholder and substitutes the question mark with the parameter, i.e. the query winds up containing this column

foo0_.[Bar@p0]

instead of

foo0_.[Bar?]

Unfortunately this is a fault in NHibernate 3.1:

http://stackoverflow.com/questions/5805617/escaping-a-question-mark-character-in-a-column-name-in-nhibernate