title: Concatenate multiple rows into a single row in LINQ
body: <p>Is is possible to concatenate multiple rows to a single row?</p>
  
  <p>for example:</p>
  
  <pre><code>IEnumerable&lt;sample&gt; sam = new List&lt;sample&gt;()
  {
      new sample{ id = 1, name = "sample 1", list = new List&lt;int&gt;{1,5,6}},
      new sample{ id = 2, name = "sample 2", list = new List&lt;int&gt;{2,9}},
      new sample{ id = 3, name = "sample 3", list = new List&lt;int&gt;{8,3,7}},
      new sample{ id = 4, name = "sample 4", list = new List&lt;int&gt;{3,4,8}},
      new sample{ id = 5, name = "sample 5", list = new List&lt;int&gt;{1,5,7}},
      new sample{ id = 6, name = "sample 6", list = new List&lt;int&gt;{6,9,7}}
  };
  </code></pre>
  
  <p>output must:</p>
  
  <pre><code>{
      new sample { id = 1, name = "sample 1", list = "1,5,6" },
      new sample { id = 2, name = "sample 2", list = "2,9" },
      new sample { id = 3, name = "sample 3", list = "8,3,7" },
      new sample { id = 4, name = "sample 4", list = "3,4,8" },
      new sample { id = 5, name = "sample 5", list = "1,5,7" },
      new sample { id = 6, name = "sample 6", list = "6,9,7" }
  };
  </code></pre>
  
  <p>That means from list the new row is now a string.</p>