HOW TO SELECT PREVIOUS ROW VALUE? [duplicate]

Answer 1

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 

Answer 2

How does following perform?

SELECT F1.ID, F1.Value, F3.Value
FROM cardevent F1
     INNER JOIN (
        SELECT F1.ID, mID = MAX(F2.ID)
        FROM cardevent F1
             INNER JOIN cardevent F2 ON F2.ID < F1.ID
        GROUP BY F1.ID
      ) F2 ON F2.id = F1.ID
     INNER JOIN cardevent F3 ON F3.ID = F2.mID
UNION ALL
SELECT F1.ID, F1.Value, 0
FROM cardevent F1
     INNER JOIN (
        SELECT ID = MIN(ID) 
        FROM cardevent
      ) F2 ON F2.ID = F1.ID
ORDER BY 1

Answer 3

I prefer TOP 1 instead of MAX(...), which IMHO should be also faster:

SELECT      C.ID, C.Value, COALESCE(C1.Value, 0)
FROM        cardevent C
LEFT JOIN   cardevent C1
        ON  C1.ID = (SELECT TOP 1 C2.ID FROM cardevent C2 WHERE C2.ID < C.ID ORDER BY C2.ID)

Answer 4

Try something like this:

SELECT C.ID, C.Value, COALESCE(C1.Value, 0)
FROM cardevent C
    LEFT JOIN cardevent C1
    ON C1.Id = (SELECT MAX(id) FROM cardevent C2 where C2.Id < C.Id)