NHibernate Query<T> with detached criteria…

问题

I have that :

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

// Here I need to execute a detached criteria, like that :
//  query.UnderlyingCriteria.Add(SpatialExpression.Within("Geo", extent));

var t = query.Select(item => new MyClassView
                                      {
                                          Name, Year, Code
                                      }

Is that a way to do that with Query ? Or maybe another way? I need a IQueryable result...

Thanks

回答1:

the linq provider does not use Criteria under the covers, it uses the AST from the HQL parser. If you really need an IQueryable then you could formulate a query like this

var ids = session.QueryOver<MyClass>()
    .UnderlyingCriteria.Add(SpatialExpression.Within("Geo", extent))
    .Select(myclass => myclass.Id)
    .List<int>();

var query = session.Query<MyClass>()
    .Where(x => ids.Contains(x.Id))
    .Select(item => new MyClassView
    {
        Name, Year, Code
    });

Note: this uses 2 roundtrips however

来源：https://stackoverflow.com/questions/9584950/nhibernate-queryt-with-detached-criteria