I have a folder hierarchy represented by the following class:
public class Folder
{
public virtual int Id { get; set; }
public virtual string Name { get; set; }
public virtual Folder ParentFolder { get; set; }
public virtual ICollection<Folder> SubFolders { get; set; }
}
In other words, each Folder can belong to a ParentFolder, as well as have SubFolders under it. I'm using Fluent NHibernate's Automapper and automatically generating the database schema using SchemaExport. I get the following table when I try to save some test folders:
Id | Name | ParentFolder_id | Folder_id
----------------------------------------------------------------
1 | Root Folder (has children) | NULL | NULL
2 | Root Folder (no children) | NULL | NULL
3 | Sub Folder | 1 | NULL
4 | Sub Sub Folder | 2 | NULL
So far so good, the ParentFolder_id column is being set correctly, although I don't know why it created another Folder_id column. Now, when I try to run the following code:
using (var session = SessionFactory.OpenSession())
{
// I'm using NHibernate 3
var rootFolder = session.Query<Folder>()
.Where(x => x.Name.StartsWith("root").First();
Console.WriteLine(rootFolder.SubFolders.Count());
}
The count returned is 0, and the following SQL is executed:
SELECT count(Id) FROM [Folder] WHERE Folder_id = 1
This SQL statement is wrong. It should be doing:
SELECT count(Id) FROM [Folder] WHERE ParentFolder_id = 1
Can anyone tell me why Fluent NHibernate is creating the extra Folder_id column and querying on it, and how I can fix it so that it properly queries the ParentFolder_id column instead? I've tried the following override with no luck:
public class FolderOverride : IAutoMappingOverride<Folder>
{
public void Override(AutoMapping<Folder> mapping)
{
mapping.HasMany(x => x.SubFolders).Inverse(); // I thought inverse might fix it, but no dice
mapping.References(x => x.ParentFolder);
}
}
