title: Return rows that have a negative equivalent
body: <p>I have a non-normalized table with several columns. I would like to return all columns that have a positive number along with a negative number of the same value.</p>
  
  <p>Example:</p>
  
  <pre><code>ID  |  Value
  -------------
  1   |  10
  1   | -10
  3   |  15
  3   |  15
  4   | -1
  5   |  4
  </code></pre>
  
  <p>Current Output:</p>
  
  <pre><code>ID | Values
  -------------
  1  |  10
  1  | -10
  3  |  15
  3  |  15
  </code></pre>
  
  <p>Desired Output:</p>
  
  <pre><code>ID | Value
  -------------
  1 |  10
  1 | -10
  </code></pre>
  
  <p>I have made a windows function as seen below that will select absolute values that are the same, but this includes pairs where there are a positive number. </p>
  
  <pre><code>select Count(*) Over (Partition By DVN, [Tran Date], [Reference Number],Description,Vendor, Abs([Maintenance Expense])) As cnt , * 
      From WorkTemp.dbo.Customer2700Combine
      Where [Maintenance Expense] Is Not Null
  Order By 1 Desc,DVN, [Tran Date], [Reference Number],Description,Vendor, Abs([NonRental Total])
  </code></pre>