如何根據時間戳和使用SQL的唯一ID爲每一行數據選擇最大值？

Question

我在我的數據庫中有一個表，我正在使用SQL查詢從中檢索數據。在我的查詢中，我正在替換一些文本並使用整數。該查詢返回下面的數據：

user_id | event_code | total_bookmarks | total_folders | folder_depth | ts 
0   8   34    6    1    128926 
0   8   35    6    1    129001 
4   8   18    2    1    123870 
6   8   30    2    1    130099 
6   8   30    2    1    132000 
6   8   30    2    1    147778 

查詢我使用的是：

SELECT 
user_id, 
event_code, 
CAST(REPLACE(data1, 'total bookmarks', '') AS INTEGER) as total_bookmarks, 
CAST(REPLACE(data2, 'folders', '') AS INTEGER) as total_folders, 
CAST(REPLACE(data3, 'folder depth ', '') AS INTEGER) as folder_depth, 
timestamp AS ts 
FROM events 
WHERE event_code = 8 

我需要什麼，以便添加到我的查詢，只選擇行對每個唯一的user_id與每個ID的最大值（時間戳）？我嘗試了MAX（timestamp），但是如果total_bookmark不同，我會得到兩個相同ID的行（例如：user_id 0，其中一行34，而另一行35）我想讓表看起來像這樣：

user_id | event_code | total_bookmarks | total_folders | folder_depth | ts 
0   8   34    6    1    129001 
4   8   18    2    1    123870 
6   8   30    2    1    147778 

Answer 1

Declare @table table (user_id int, event_code int, total_bookmarks int, total_folders int, folder_depth int, ts decimal(18,0)) 
Insert into @table (user_id , event_code , total_bookmarks , total_folders , folder_depth , ts) 
Values (0,8,34,6,1,128926), 
     (0,8,34,6,1,129001), 
     (4, 8, 18 , 2, 1, 123870), 
     (6, 8, 30, 2, 1, 130099), 
     (6, 8, 30, 2, 1, 132000), 
     (6, 8, 30, 2, 1, 147778) 

Select * from @table 

Select  user_id,event_code,total_bookmarks,total_folders,folder_depth,ts 
From  (
      Select  RANK() over (Partition by user_id 
            Order by ts desc 
            ) as Rank, 
         user_id,event_code,total_bookmarks,total_folders,folder_depth,ts 

      From  @table 
      ) D1 
Where  D1.Rank = 1