title: How to lock table in sequelize, wait until another request to be complete
body: <p><strong>Description:</strong></p>
  
  <p>I have one table in db say <code>Table1</code>. having only one column <code>AppNo(numeric)</code> and only single row, and current value is <code>0</code></p>
  
  <p>I have created API in <code>node.js</code> using <code>Sequelize</code> ORM named <code>UpdateAppNo</code>.</p>
  
  <p>Whenever <code>UpdateAppNo</code> api called value of <code>AppNo</code> should increment by <code>1</code>.</p>
  
  <p><strong>What i want:</strong></p>
  
  <p>If 2 or more simultaneous request comes at a time, current request should wait until previous request to complete.</p>
  
  <p><strong>What happening now:</strong></p>
  
  <p>If previous request is in process, then current request throws an error.</p>