title: How to determine which values had a status change from the prior month SQL
body: <p>I have the dataset in the image</p>
  
  <p>105665 Status changed 03-2017, Decommissioned from the prior month of 02-2017, Pending Decommissioned.</p>
  
  <p>On a monthly basis, I need to determine which Assets have changed Status from the "prior" month.  I was thinking a new field is needed that tells me which Assets have changed status from the prior month but don't know how to determine that logic.  I will also need a count of Assets of how many moved from Pending Decommissioned to Decommissioned for example or from Installed to Pending Decommissioned but I'll worry about that part later.<a href="https://i.stack.imgur.com/Rcfix.jpg" rel="nofollow noreferrer">enter image description here</a></p>
  
  <p>(I have found similar cases but not exactly like this one so although I still tried those solutions, none of them worked for me).</p>
  
  <p>Many thanks!</p>