实体框架查找与哪里 [英] Entity Framework Find vs. Where
问题描述
.Find(id)
和之间有显着差异。(x => x.Id == id) code>应该强迫我使用
? .Find()
超过$ code> .Where()/。First()
我想象, .Find()
会更有效率,但是效率要高得多我应该避免 .Where()/。First()
?
我问的原因是我正在使用在我的测试中,通用的FakeDbSet使得它很容易实现假的结果,到目前为止,我发现我必须继承该类并提供 .Find()
的自定义实现,而如果我用编写我的代码.Where()/。First()
我不需要做这个额外的工作。
重点在于, find
通过搜索上下文的本地缓存开始,然后如果没有匹配,则发送对db的查询。
其中
总是向db发送查询。
与EF 4. * ,我以前认为由 find
生成的sql太复杂了,在某些情况下会导致性能问题。所以我总是使用其中
甚至使用EF 5.我应该检查由$ 5生成的s $ c找到与EF 5。 p>
所以在本文中, find
更好,因为他使用缓存。
Is there a significant difference between .Find(id)
and .Where(x = >x.Id == id)
that should compel me to use .Find()
over .Where()/.First()
?
I would imagine that .Find()
would be more efficient but is it so much more efficient that I should avoid .Where()/.First()
?
The reason I ask is that I am using a generic FakeDbSet in my tests to make it easy to implement fake results and so far I have found that I must inherit that class and provide a custom implementation of .Find()
whereas if I write my code with .Where()/.First()
I don't need to do that extra work.
The point is that find
starts by searching in the local cache of the context and then, if no match, sends a query to the db.
where
always sends a query to the db.
With EF 4.*, I used to think that sql generated by find
was too complex and, in some cases, leads to a performance issue. So I always use where
even with EF 5. I should check the sql generated by find
with EF 5.
So in the paper, find
is better because he uses the cache.
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