Compare dataset or a better idea

Question

How do I compare values of one data set from another.

1st dataset [\"proper records\"] is coming from SQL Server with column names

Answer 1

To get all the records from 2nd dataset that match the records from the 1st dataset would be something like this:

IEnumerable list3 = list2.Where(l2=>list1.Contains(l1=>l1.subsNumber == l2.subsNumber));

Something along those lines!