NHibernate查询与独立的标准... [英] NHibernate Query<T> with detached criteria...

问题描述

我有:

var query = session.Query<MyClass>();    

// Here I need to execute a detached criteria, like that :
//  query.UnderlyingCriteria.Add(SpatialExpression.Within("Geo", extent));

var t = query.Select(item => new MyClassView
                                      {
                                          Name, Year, Code
                                      }

这是使用Query做到这一点的方法吗?或者也许是另一种方式?我需要一个IQueryable结果...

Is that a way to do that with Query ? Or maybe another way? I need a IQueryable result...

谢谢

推荐答案

linq提供程序在幕后不使用Criteria，而是使用HQL解析器中的AST.如果您确实需要IQueryable，则可以制定这样的查询

the linq provider does not use Criteria under the covers, it uses the AST from the HQL parser. If you really need an IQueryable then you could formulate a query like this

var ids = session.QueryOver<MyClass>()
    .UnderlyingCriteria.Add(SpatialExpression.Within("Geo", extent))
    .Select(myclass => myclass.Id)
    .List<int>();

var query = session.Query<MyClass>()
    .Where(x => ids.Contains(x.Id))
    .Select(item => new MyClassView
    {
        Name, Year, Code
    });

注意:但是，这需要2次往返行程

Note: this uses 2 roundtrips however

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