Sql – HOW TO SELECT PREVIOUS ROW VALUE?

ms-accesssql

How to get a value from previous result row of a SELECT statement

If we have a table called cardevent and has rows [ID(int) , Value(Money) ] and we have some rows in it, for example

ID --Value

1------70 
1------90
2------100
2------150
2------300 
3------150 
3------200 
3-----250 
3-----280 

so on…

How to make one Query that get each row ID,Value and the previous Row Value in which data appear as follow

ID --- Value ---Prev_Value

1 ----- 70 ----------  0 
1 ----- 90 ---------- 70
2 ----- 100 --------  90 
2 ------150 -------- 100
2 ------300 -------- 150
3 ----- 150 -------- 300 
3 ----- 200 -------- 150 
3 ---- 250 -------- 200 
3 ---- 280 -------- 250 

so on.

i make the following query but it's so bad in performance in huge amount of data

SELECT cardevent.ID, cardevent.Value, 
      (SELECT F1.Value
       FROM cardevent as F1 
       where F1.ID = (SELECT  Max(F2.ID)
                      FROM cardevent as F2 
                      WHERE F2.ID < cardevent.ID)
      ) AS Prev_Value
FROM cardevent

So can anyone help me to get the best solution for such a problem ?

Best Solution

This one should work fine for both databases:

SELECT cardevent.ID, cardevent.Value, 
  (SELECT TOP 1 F1.Value
   FROM cardevent as F1
   WHERE F1.ID < cardevent.ID
   ORDER BY F1.ID DESC
   ) AS Prev_Value
FROM cardevent

Update: Assuming that ID is not unique, but that the combination of ID and Value is unique (you must specify what imposes your ordering on the table, so one knows what is the previous row), you must use this query:

select cardevent.ID, cardevent.Value, 
    (select TOP 1 F1.Value from cardevent as F1
     where (F1.ID < cardevent.ID) or (F1.ID = cardevent.ID and F1.Value < cardevent.Value)
     order by F1.ID DESC, F1.Value DESC
    ) AS Prev_Value
from cardevent