title: Compare a column itself to check whether it have duplicated value in EXCEL
body: <p>Suppose I have a column called item code as below:</p>
  
  <pre><code>-----  ------
  |row|  |code|
  -----  ------
  |1  |  |A123|
  -----  ------
  |2  |  |B123|
  -----  ------
  |...|  |....|
  -----  ------
  |n  |  |A123|
  -----  ------
  </code></pre>
  
  <p>The value in the column of code may appear more then one time, how can I use Excel formula or any method in Excel to check the duplicated record in a column?</p>
  
  <p>Thanks</p>