Fluent nhibernate batch save

Question

I have xml file that I am reading in and uppdating existing records in a database.

I read the xml into a list of c# objects and iterate through them finding the corresponding record in the datbase and update it from the xml/c# values.

I then save this object - but is there any way in fluent nihibernate to add the object to a list ( could be 1000s of records) and bacth save

Bottom line it is performance I am afer - I have been using subsonic 2 and 3 and have opted for subsonic 2 as it was way faster - but I was just wonder any views on using fluent nhibernate to do this - examples etc

score 0 · Answer 1 · answered Nov 08 '11 at 09:35

the session has a cache which is what you want. if you have batching enabled in the configuration of the sessionfactory then the following would batch the updates

using (var tx = session.BeginTransaction())
{
    const int BATCH_SIZE = 1000;
    IList<MyObjects> myobjects = ReadInXML();
    Dictionary<int, MyObjects> batch = new Dictionary<int, MyObjects>(BATCH_SIZE);
    for (int i = 0; i < myobjects.Count; i++)
    {
        batch.Add(myobjects[i].Id, myobjects[i]);
        if (batch.Count < BATCH_SIZE)
            continue;

        var entities = session.QueryOver<MyEntity>()
            .WhereRestrictionOn(x => x.Id).IsIn(batch.Keys)
            .List();

        foreach (var entity in entities)
        {
            Update(entity, batch[entity.Id]);
        }

        // the session knows all entities it has loaded, no need for session.Update();
        session.Flush();
        // remove all processed entities from the session cache to speed up things
        session.Clear();
        // prepare for next batch
        batch.Clear();
    }

    tx.Commit();
}

Fluent nhibernate batch save

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