用户定义函数输出进行的Nhibernate过滤 [英] Nhibernate filtering by user defined function output

问题描述

我是NHibernate的新手，到目前为止一切都很好，但是我遇到了一个问题，我不确定如何解决.基本上，我需要按用户定义函数的输出进行过滤.如果我用SQL编写，这就是我要写的:

I'm reasonably new to NHibernate and everything has been going pretty well so far but I've come across a problem I'm not exactly sure of how to go about solving. Basically I need to filter by the output of a User Defined function. If I was writing in SQL this is what I'd write:

declare @Latitude decimal
declare @Longitude decimal
declare @radius int

set @Latitude = -118.4104684 
set @Longitude = 34.1030032

select  * 
from    store
where   dbo.CalculateDistance([Latitude], [Longitude], @Latitude, @Longitude) < @radius

我已经看到了我认为不合适的公式属性，命名查询以及创建自己的方言扩展名的示例(这似乎有点过头了).我本来以为有一种更直接的方法，但是我似乎找不到一个整洁的例子.

I've seen the formula attribute which I don't think is appropriate, named queries and examples of creating your own dialect extension (which seemed a little over kill). I would've thought there was a more straight forward way of doing it but I can't seem to find a tidy example.

推荐答案

您可以在休眠查询中使用SQL表达式.假设您已映射Store类型，则可以编写以下查询:

You could use SQL expression in your hibernate queries. Assuming you've mapped a Store type you could write the following query:

var result = session
    .CreateCriteria<Store>()
    .Add(Expression.Sql(
        "dbo.CalculateDistance({alias}.Latitude, {alias}.Longitude, ?, ?) < ?",
        new object[] { 
            -118.4104684d, 
            34.1030032d, 
            100 
        },
        new IType[] { 
            NHibernateUtil.Double, 
            NHibernateUtil.Double, 
            NHibernateUtil.Int32 
        }
    ))
    .List<Store>();

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