title: Joining 2 tables data in Linq with Contains
body: <p>I have a property '<strong>CountryId</strong>' in res1<code>list and I want to use it in join condition if c.CountryId exists in res1 but intellisense doesnt have Contains() method on</code>c.CountryId<code>, all I have in</code>c.ToString()<code> ,</code>c.CompareTo()` and other inbuilt functions. How do I check if c.CountryId is among res1's CountryId?</p>
  <pre><code> List&lt;ClassA&gt; res1 = new List&lt;ClassA&gt;();
    
    var result = await (from enumeration in db.Enumerations e
          join cust c in e.Id equals c.Id
          where c.CountryId .... 
          select c);
  </code></pre>