title: SQL 'IN' Operator with LINQ in Visual Studio Lightswitch
body: <p>Very often I have need for queries similar to this:</p>
  
  <pre><code>SELECT * FROM Customers  
  WHERE City IN ('Paris','London');
  </code></pre>
  
  <p>I have some list (most often strings). When list is small (like this in example), it is not such a problem, I can write something like this (C#):  </p>
  
  <pre><code>Customers custs = this.DataWorkspace.ApplicationData.Customers;
  var filteredcustomers = custs.Where(c=&gt;c.City == "Paris" || c=&gt;c.City == "London");
  </code></pre>
  
  <p>but if I have bigger list, it's a little clumsy. 
  I've tried this (from some forum):  </p>
  
  <pre><code>List&lt;string&gt; months = new List&lt;string&gt;() {"Jan", "Feb", "Mar"......"Dec"};
  Customers custs = this.DataWorkspace.ApplicationData.Customers; 
  var filteredcustomers = custs.Where(c =&gt; months.Contains(c.City));
  </code></pre>
  
  <p>but I get run-time error:<br>
  "{System.NotSupportedException:
  The expression value(System.Collections.Generic.List`1[System.String]).Contains([10007].City) is not supported. ..."</p>