在Linq和Nhibernate中使用Count（）时，不支持指定的方法

Question

When I am using .Count() I am getting this error:

the specified method not supported

At this line am getting error like Sql not found :

session.Query<Table>().Select(x => new { x.Id }).Distinct();

This is the full code:

var List = session.Query<Table>().Select(x => new { x.Id }).Distinct();
foreach (var id in SelectedIds.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries))
{
    var count = List.Where(x => x.Id == Int32.Parse(id)).Count();
    if (count > 0)
    {

    }
}

Is it problem with Nhibernate or am i missing something?

Answer 1

Try to put out the cast like this:

int idCompare = Int32.Parse(id);
var count = List.Where(x => x.Id == idCompare).Count();

Linq is not able to convert every .NET Framework advanced function to sql.

Maybe this solves your issue.

When you need to check whether a .NET method is available in linq you might want to check this source and also this