title: MySQL Workbench: merging multiple rows into one row using same call_ID
body: <p>The data is like:</p>
  
  <pre><code>CallID | callin | callout
  
   456   |  16267777 | *123
  
     456 | *123      |19095351
  
    789  | 1323789   |  *123
  
     789 |  *123     |180515978
  </code></pre>
  
  <p>(*123 is the system extension number )</p>
  
  <p>Table name : call_history</p>
  
  <p>Now I want to regroup the data to become:</p>
  
  <pre><code> CallID           callin           callout
  
   456             16267777         19095351
  
   789             1323789          180515978
  </code></pre>
  
  <p>How do I do it ? By using Selfjoin? GROUP?</p>
  
  <p>Thank you!</p>