Database: Select last non-null entries

Question

Here\'s a question I\'ve been racking my brain over. Let\'s say I have a table that has a series of timestamps and a part number as the primary key. The table stores incremental

Answer 1

For only one part this should give you an answer .. thanks to ruakh

But I dont like this version ..

SELECT 
    (SELECT timestamp  FROM part_changes WHERE part = $part 
    ORDER BY timestamp DESC
    LIMIT 1) as timestamp,

    (SELECT x-pos FROM part_changes WHERE part = $part and x-pos IS NOT NULL
    ORDER BY timestamp DESC
    LIMIT 1) as xpos,

    (SELECT y-pos FROM part_changes WHERE part = $part and  y-pos IS NOT NULL
    ORDER BY timestamp DESC
    LIMIT 1) as ypos,

    (SELECT status FROM part_changes WHERE part = $part and status IS NOT NULL
    ORDER BY timestamp DESC
    LIMIT 1)) as status