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The Perstent API type I used for code generation is "Static Methods", I think is the most simple and ok for me.

I created a class called dao.cs so it contains every access to the database and connections. It looks like this:

public class dao
{
private PersistentManager persistenceManager = HMIPersistentManager.Instance();

private static dao instance = null;

private dao()
{
}

public static dao getInstance()
{
if (instance == null)
instance = new dao();
return instance;
}

public Recipe getRecipeByID(int id)
{
PersistentTransaction t = this.persistenceManager.GetSession().BeginTransaction();

Recipe a = Recipe.LoadRecipeByORMID(id);

t.Commit(); // <<-- exception here: already opened conexion or ID already in use....
return a;
}

/* more methods... */


}

The problem is, when executing the project, sometimes it throws an exception on the "t.Commit();" line. I would like to implement the best way for a web application: multiple users accessing the database, and everything running fine.

Do I need to use a lock like:
PersistentManager.instance().getSession().lock(obj, LockMode.NONE);

Where do I put it? Which lockmode choose?

Thanks in advance]]> http://forums.visual-paradigm.com/posts/2739#20472.html http://forums.visual-paradigm.com/posts/2739#20472.html
When running in web environment, please make sure have

1. close session before return values

2. running thread based session

XXPersistentManager.SetSessionType(PersistentManager.SessionType.THREAD_BASE);

Hope this helps.

Best regards,
Rain
]]> http://forums.visual-paradigm.com/posts/2739#20491.html http://forums.visual-paradigm.com/posts/2739#20491.html