title: Selecting Second row if available if not first in SQL
body: <p>I have a table that looks like below:</p>
  
  <p><img src="https://i.stack.imgur.com/kVroS.png" alt="enter image description here"></p>
  
  <p>i want to Select Operator entry that corresponds to RowNumber 2 of InstanceNumber 1 and rownumber 1 of other instances. This is one example where only instancenumber 1 has two rownumber's but I want to able to pick last rownumber of each intances. Any help is appreciated.</p>