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c#nhibernatehibernatebatch-filebatch-processing

How to delete multiple db entities with Nhibernate?

What is the best practice for this problem? Is there any batching features built-in?

Sample code:

using (ITransaction transaction = _session.BeginTransaction())
{
   _session.Delete("FROM myObject o WHERE  o.Id = IN(1,2,...99999)");
   transaction.Commit();
}

Thanks in advance.

Solution

  • HQL supports the IN clause, and if you use setParameterList you can even pass in a collection.

    var idList = new List<int>() { 5,3,6,7 };

_session.CreateQuery("DELETE MyDataClass o WHERE o.Id IN (:idList)")
    .SetParameterList("idList", idList)
    .ExecuteUpdate();

    Be aware, like mentioned by ddango in a comment, that relationship cascades specified in your objects will not be executed since running an HQL query simply translates to a DB query and does not actually load any entity objects.