Select Most Recent States From History Table

Question

I have inherited a table with a structure something like this:

ID   Name   Timestamp   Data
----------------------------
1    A      40          ...
2    A               


        

Answer 1

SQL Server 2000:

SELECT
  ID, Name, Timestamp, Data
FROM
  DataTable
  INNER JOIN
  (
     SELECT ID, MAX(Timestamp) Timestamp FROM DataTable GROUP BY ID
  ) latest ON 
    DataTable.ID = Latest.ID AND 
    DataTable.Timestamp = Latest.Timestamp