title: SQL query to find duplicate rows, in any table
body: <p>I'm looking for a schema-independent query.  That is, if I have a <code>users</code> table or a <code>purchases</code> table, the query should be equally capable of catching duplicate rows in either table without any modification (other than the <code>from</code> clause, of course).</p>
  
  <p>I'm using T-SQL, but I'm guessing there should be a general solution.</p>