protected override LinqExpression VisitQuerySource(QuerySourceExpression expr) { if (rootCriteria == null) { if (!string.IsNullOrEmpty(this.entityName)) { rootCriteria = session.CreateCriteria(entityName, expr.Alias); } else { rootCriteria = session.CreateCriteria(expr.ElementType, expr.Alias); } options.Execute(rootCriteria); } return(expr); }