How can I use LINQ to find the Intersect between two properties of the same collection?

Posted by aponzani on Stack Overflow See other posts from Stack Overflow or by aponzani
Published on 2010-04-28T21:27:28Z Indexed on 2010/04/28 21:47 UTC
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LINQ

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intersect

Given an IList<Foo> with a data set that looks like this:

ID   CHILD  PARENT TYPE  
1   102    101    UPSELL  
1   103    101    UPSELL  
2   102    101    BONUS  
2   104    103    BONUS  
3   102    101    BONUS  
4   102    101    PRODUCT  
4   104    102    PRODUCT

How can I use LINQ to find the intersection of Parent and Child values withing each ID? Desired output is

ID   CHILD  PARENT TYPE 
4   102    101    PRODUCT

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