title: Date Difference in MySQL to calculate age
body: <p>I have a problem regarding the <code>datediff</code> MYSQL function, I can use it and it is simple. But I don't understand how to use it to collect differences within the table field. E.g.</p>
  
  <p>I have a column <code>dob</code> and I want to write a query that will do something like</p>
  
  <pre><code>select dateDiff(current_timeStamp,dob) 
  from sometable 'here dob is the table column
  </code></pre>
  
  <p>I mean I want the difference from the current date time to the table field <code>dob</code>, each query result is the difference, the age of the user.</p>