title: Error 1241 Operand should contain 2 column(s)
body: <p>My query : <a href="http://pastebin.com/8c2rLrRk" rel="nofollow noreferrer">http://pastebin.com/8c2rLrRk</a></p>
  
  <p>In this 3rd case 2nd when condition is causing the issue, if i comment that then query is running well. So pls let me know where the loophole in this syntax.</p>