NHibernate Lazy =“额外". [英] NHibernate Lazy="Extra"

问题描述

关于lazy ="extra"到底具有什么功能，是否有很好的解释?

Is there a good explanation out there on what exactly lazy="extra" is capable of?

我所见过的所有帖子都重复了一个事实，即它将对MyObject.ItsCollection.Count的引用转换为select count(*)查询(假设它们尚未加载).

All the posts I've seen all just repeat the fact that it turns references to MyObject.ItsCollection.Count into select count(*) queries (assuming they're not loaded already).

我想知道它是否具有更强大的功能，例如将MyObject.ItsCollection.Any(o => o.Whatever == 5)转换为SELECT ...EXISTS查询.

I'd like to know if it's capable of more robust things, like turning MyObject.ItsCollection.Any(o => o.Whatever == 5) into a SELECT ...EXISTS query.

文档的第18.1节仅涉及该内容.我不是NH开发人员，因此如果不花点时间完成所有工作，就无法真正进行实验和观看SQL Profiler.我只是在寻找某种描述此功能功能的参考.

Section 18.1 of the docs only touches on it. I'm not an NH developer, so I can't really experiment with it and watch SQL Profiler without doing a bit of work getting everything set up; I'm just looking for some sort of reference describing what this feature is capable of.

谢谢！

推荐答案

对于版本2.x，它仅用于将collection.Count()转换为select count，据我在源代码中所见，它将还允许构造物collection[5]获取该特定实体(索引为5)，而不是对整个集合进行水化处理.

for version 2.x it is only used to translate a collection.Count() into a select count and as far as i can see in the source, it will also allow the construct collection[5] to fetch that particular entity (with index 5) instead of hydrating the whole collection.

对于3.x版，我没有在发行说明中看到任何相关内容

For version 3.x i didn't see anything related in the release notes

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