Nhibernate QueryOver。 OrderBy 使用字符串属性名称。

Question

我正在重构旧式查询 CreateCriteria()至 QueryOver() .我的 Wcf 服务得到 string PropertyName对查询结果进行排序。对于 IQueryable我使用动态 LINQ 来做这样的排序，对于 CreateCriteria() - AddOrder() .

IList<object[]> result =
            GetSession()
                .QueryOver(() => activity)
                .JoinAlias(() => activity.ActivityLicense, () => license)
                .Select(Projections.ProjectionList()
                            .Add(Projections.Count<Activity>(e => e.Id), "ActivityCount")
                            .Add(Projections.Group(() => license.SerialNumber), "SerialNumber")
                            .Add(Projections.Count<Activity>(e => e.MacAdress), "MacAddressCount")
                            .Add(Projections.Count<Activity>(e => e.IpAdress), "IpAddressCount")
                )
                .OrderByAlias("ActivityCount") // Compilation Error - I need such extension method
                .List<object[]>();

任何建议如何在字符串属性名称的情况下进行排序？

PS:我无法使用 LINQ to Nhibernate: LINQ to NHibernate - .GroupBy().Skip().Take() cause an exception

谢谢!

Answer 1

您可以随时获得 UnderlyingCriteria ...

var q = GetSession()
                .QueryOver(() => activity)
                .JoinAlias(() => activity.ActivityLicense, () => license)
                .Select(Projections.ProjectionList()
                            .Add(Projections.Count<Activity>(e => e.Id), "ActivityCount")
                            .Add(Projections.Group(() => license.SerialNumber), "SerialNumber")
                            .Add(Projections.Count<Activity>(e => e.MacAdress), "MacAddressCount")
                            .Add(Projections.Count<Activity>(e => e.IpAdress), "IpAddressCount")
                );


q.UnderlyingCriteria.AddOrder(new Order("ActivityCount", true));

var results = q.List();

或作为 IQueryOver 的扩展方法

public static IQueryOver<T,T> OrderByAlias(this IQueryOver<T,T> q, string aliasName, bool ascending)
{
    q.UnderlyingCriteria.AddOrder(new Order(aliasName, ascending));
    return q;
}