title: Add a column in a table with a first letter must be 0?
body: <p>I want to add a column <code>S_order_no</code> in a table <code>Sales_order</code> with a constraint that the first letter must start with <code>0</code>. So that if we try to write the first letter other than <code>0</code> it throws an error.
  Is it possible?. If yes please explain with an example.</p>
  
  <p><img src="https://i.stack.imgur.com/y84az.png" alt="sales_order table"></p>