title: How do I write a multikey query in MongoDb and C#?
body: <p>In our Mongo database we have a collection indexed by "StoreId" and "ItemId". The following query brings back all combinations of product stores (total of 9 documents) included in the "In" list. </p>
  
  <pre><code>var productQuery = Query.In("ItemId", new BsonArray(new List&lt;int&gt; {1, 2, 3}));
  var storeQuery = Query.In("StoreId", new BsonArray(new List&lt;int&gt; {1, 2, 3}));
  var queryToBringNineDocuments = Query.And(productQuery, storeQuery);
  </code></pre>
  
  <p>How do I write a query that brings me back documents with keys in the following item-store tuple list? </p>
  
  <pre><code>var neededProductStores = new List&lt;Tuple&lt;int, int&gt;&gt;
  {
      new Tuple&lt;int, int&gt;(1, 2),
      new Tuple&lt;int, int&gt;(1, 3),
      new Tuple&lt;int, int&gt;(2, 1),
      new Tuple&lt;int, int&gt;(3, 2)
  };
  
  var queryToBringFourDocuments = ?;
  </code></pre>