C# NHibernate dynamically add Where clauses (jqgrid)

Question

Is it possible to add where clauses dynamically to an NHibernate Query?

I have a collection of Clauses I need to Loop through and add a Where clause if required - i.e. if the user has entered multiple search criteria.

I Can write single queries, no problem, like this: get All Names beginning with 'a':

IEnumerable<Customer> customers = nHibernateSession.Query<Customer>().Where(x => x.Name.StartsWith("a")).ToList();

but I do not know how to then Add another where clause to this Effectively I need something that is like this:

foreach (clauses in SelectionClauses)
{
    //add a .Where(Clause) to The Session.Query
}

I suspect That The nHibernateSession.Query cannot be used this way... Does anyone know How to do this?

Answer 1

You can do this with the Linq provider (session.Query) by doing something like:

var query = session.Query<MyClass>();

foreach(var clause in clauses)
    query = query.Where(clause.BuildExpression());

Where BuildExpression returns Expression> for example

However this can get painful if you are using string name for your properties, and it will be a lot easier to achieve your result using session.QueryOver or session.CreateCriteria both of which support querying properties by their name instead of via expressions.