get last low in linq : I have 1 table that have PK is string I can't get last row 
when I use `order by code desc` code is PK

last row is **9999**

[![enter image description here][1]][1]


but real last row is **73858**

[![enter image description here][2]][2]


  [1]: https://i.stack.imgur.com/yIPLn.png
  [2]: https://i.stack.imgur.com/9Rnwi.png



Help me please T__T

I'm from Thailand sorry if incorrect language