Self-Referencing HasMany Relationship in Fluent NHibernate and MVC3
I have a Word model for a dictionary/thesaurus:
public class Word
{
public virtual string Text { get; set; }
public virtual IList<Word> Synonyms { get; set; }
public virtual IList<Word> Antonyms { get; set; }
}
Where each Word has many Synonyms and Antonyms. Word has a mapping of:
public class WordMapping : ClassMap<Word>
{
Id(x => x.Text);
HasMany(x => x.Synonyms);
HasMany(x => x.Antonyms);
}
In my controller, I have a simple lookup 开发者_开发问答method for a word:
public ActionResult Word(string word)
{
using (var session = MvcApplication.SessionFactory.OpenSession())
{
using (var transaction = session.BeginTransaction())
{
var result = session.QueryOver<Word>()
.Where(w => w.Text == word)
.SingleOrDefault();
if(result == null)
RedirectToAction("InvalidWord");
ViewBag.Synonyms = result.Synonyms.Select(t => t.Text);
ViewBag.Antonyms = result.Antonyms.Select(t => t.Text);
return View(result);
}
}
}
When I print out the ViewBag collections in my view, they are both the same. They are some seemingly arbitrary selection of elements from both bags, but not the whole bags.
Update: Below is my code to commit the Words to the database, if that helps. When I print out words
after the commit, all the synonyms are correct.
List<Word> words;
...
using (var session = MvcApplication.SessionFactory.OpenSession())
{
// populate the database
using (var transaction = session.BeginTransaction())
{
foreach (var word in words)
session.Save(word);
transaction.Commit();
}
}
PrintWords(words);
Try using an identity column Id
instead of the Text
property:
public class Word
{
public virtual int Id { get; set; }
public virtual string Text { get; set; }
public virtual IList<Word> Synonyms { get; set; }
public virtual IList<Word> Antonyms { get; set; }
}
and then:
Id(x => x.Id);
Map(x => x.Text);
HasMany(x => x.Synonyms);
HasMany(x => x.Antonyms);
UPDATE:
Here's a full working example (using SQLite and a console application to simplify but similar techniques could be applied in your web application):
// Domain layer
public class Word
{
public virtual int Id { get; set; }
public virtual string Text { get; set; }
public virtual IList<Word> Synonyms { get; set; }
public virtual IList<Word> Antonyms { get; set; }
}
// Mapping layer
public class WordMapping : ClassMap<Word>
{
public WordMapping()
{
Id(x => x.Id).UnsavedValue(0);
Map(x => x.Text);
HasMany(x => x.Synonyms).Cascade.AllDeleteOrphan();
HasMany(x => x.Antonyms).Cascade.AllDeleteOrphan();
}
}
// Data access layer
class Program : InMemoryDatabase
{
static void Main(string[] args)
{
using (var p = new Program())
{
// save some dummy data into the database
var word = new Word
{
Text = "myword",
Synonyms = new[]
{
new Word { Text = "synonym 1" },
new Word { Text = "synonym 2" },
}.ToList(),
Antonyms = new[]
{
new Word { Text = "antonym 1" },
}.ToList()
};
using (var tx = p.Session.BeginTransaction())
{
p.Session.Save(word);
tx.Commit();
}
// and now let's query the database
using (var tx = p.Session.BeginTransaction())
{
var result = p.Session
.QueryOver<Word>()
.Where(w => w.Text == "myword")
.SingleOrDefault();
var synonyms = result.Synonyms.Select(t => t.Text).ToArray();
Console.WriteLine("-- Synonyms --");
foreach (var item in synonyms)
{
Console.WriteLine(item);
}
var antonyms = result.Antonyms.Select(t => t.Text).ToArray();
Console.WriteLine("-- Antonyms --");
foreach (var item in antonyms)
{
Console.WriteLine(item);
}
}
}
}
}
public abstract class InMemoryDatabase : IDisposable
{
private static Configuration _configuration;
private static ISessionFactory _sessionFactory;
protected ISession Session { get; set; }
protected InMemoryDatabase()
{
_sessionFactory = CreateSessionFactory();
Session = _sessionFactory.OpenSession();
BuildSchema(Session);
}
private static ISessionFactory CreateSessionFactory()
{
return Fluently.Configure()
.Database(SQLiteConfiguration.Standard.InMemory().ShowSql())
.Mappings(M => M.FluentMappings.AddFromAssemblyOf<WordMapping>())
.ExposeConfiguration(Cfg => _configuration = Cfg)
.BuildSessionFactory();
}
private static void BuildSchema(ISession Session)
{
SchemaExport export = new SchemaExport(_configuration);
export.Execute(true, true, false, Session.Connection, null);
}
public void Dispose()
{
Session.Dispose();
}
}
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