需要帮助优化使用Restrictions.In（..）的NHibernate条件查询

Question

我正在试图弄清楚是否有一种方法可以通过子查询或其他更优化的方式严格使用Criteria和DetachedCriteria来执行以下操作。 NameGuidDto只不过是一个具有字符串和Guid属性的轻量级对象。

public IList<NameGuidDto> GetByManager(Employee manager)
{
    // First, grab all of the Customers where the employee is a backup manager.
    // Access customers that are primarily managed via manager.ManagedCustomers.
    // I need this list to pass to Restrictions.In(..) below, but can I do it better?
    Guid[] customerIds = new Guid[manager.BackedCustomers.Count];

    int count = 0;
    foreach (Customer customer in manager.BackedCustomers)
    {
        customerIds[count++] = customer.Id;
    }

    ICriteria criteria = Session.CreateCriteria(typeof(Customer))
                                .Add(Restrictions.Disjunction()
                                                 .Add(Restrictions.Eq("Manager", manager))
                                                 .Add(Restrictions.In("Id", customerIds)))
                                .SetProjection(Projections.ProjectionList()
                                                          .Add(Projections.Property("Name"), "Name")
                                                          .Add(Projections.Property("Id"), "Guid"))

    // Transform results to NameGuidDto
    criteria.SetResultTransformer(Transformers.AliasToBean(typeof(NameGuidDto)));

    return criteria.List<NameGuidDto>();
}

Answer 1

return Session.CreateCriteria<Customer>()
    .CreateAlias("BackupManagers", "bm", LeftOuterJoin)
    .Add(Restrictions.Disjunction()
        .Add(Restrictions.Eq("Manager", manager))
        .Add(Restrictions.Eq("bm.Id", manager.Id)))
    .SetProjection(Projections.Distinct(Projections.ProjectionList()
        .Add(Projections.Property("Name"), "Name")
        .Add(Projections.Property("Id"), "Guid")))
    .SetResultTransformer(Transformers.AliasToBean(typeof(NameGuidDto)))
    .List<NameGuidDto>();

我在那里投了一个明显的东西，因为我不确定是否有可能备份和主要是同一个人。