选择与Linq to Entities不同(Select Distinct with Linq to Entities)

 对这个问题的一个扩展问题在这里提出 ，我试图做同样的功能，即 
 
IEnumerable<Customer> filteredList = originalList
  .GroupBy(customer => customer.CustomerId)
  .Select(group => group.First());
 
 在评论中，这暗示着，如果它是Linq实体，并且肯定不适合我，那么我将得到一个空结果集。 
 
 
 
 对我不起作用！ 即使我尝试了'FirstOrDefault'，但它不起作用。 - JatSing 11年9月25日在13:55 
 
 
 @JatSing：您必须使用Linq to Entities。 - 乔希Mouch 12年2月14日在14:45 
 
 
 因此，如果上述不适用于实体的Linq，我将如何去分组一个由两列设置的EntityType消息的IEnumerable，然后得到每个组的第一行？ 

An expansion on the question asked here, I am trying to do the same functionality, namely 
 
IEnumerable<Customer> filteredList = originalList
  .GroupBy(customer => customer.CustomerId)
  .Select(group => group.First());
 
which in the comments, it was implied that this will not work if it is Linq to Entities and certainly isn't working for me, I get a null result set.
 
 
 
Doesn't work for me ! Even I tried 'FirstOrDefault' it didn't work. – JatSing Sep 25 '11 at 13:55
 
 
@JatSing: You must be using Linq to Entities. – Josh Mouch Feb 14 '12 at 14:45
 
 
So if the above doesn't work for Linq to Entities, how would I go about grouping an IEnumerable of an EntityType message set by two columns, and then get the first row of each group?

原文：https://stackoverflow.com/questions/40387427