How to get the unique item from sharepoint list

Question

    List Name Social
   Column name Category(Choice Field),Values(Text )

   Category    values              modified
 ................................................
       Facebook    sameple update      10/09/2014 11.30
     Twitter     samepl trweets      10/09/2014 11.31   
       LinkedIn    testaibisi         10/09/2014 11.30
     Twitter     2nd one             10/09/2014 11.32

how to get the recent modified item from this list,i need one item each category like

  like my out put is shoul be,
 Twitter     2nd one           10/09/2014 11.32 
 Facebook    sameple update     10/09/2014 11.30

LinkedIn    testaibisi         10/09/2014 11.30

Any idea to retrieve the item form based on the category?

Answer 1

I haven't known SharePoint provide or not, but in my opinion you can get this in two ways:

1. First of all you need to write CAML query and do many groupby, stuff... like in SQL
2. The second, get all item of the list and use algorithm to detect and get the unique item.