Actualizar Campo con Row Anterior

[Libras]

Código SQL:

CREATE TABLE #temp
(
dato1 INT,
dato2 INT,
dato3 INT
)
 
 
INSERT INTO #temp VALUES (323,  308,    631)
INSERT INTO #temp VALUES (0,    0,  0)
INSERT INTO #temp VALUES (0 ,1, 0)
INSERT INTO #temp VALUES (0 ,9, 0)
INSERT INTO #temp VALUES (0 ,1, 0)
INSERT INTO #temp VALUES (0 ,3, 0)
 
DECLARE @x INT
DECLARE @anterior INT
DECLARE @NEXT INT
DECLARE @valor INT
 
CREATE TABLE #temp3
(
dato1 INT,
dato2 INT,
dato3 INT,
rn INT
)
 
SET @x=1
 
SELECT *,IDENTITY(INT,1,1) rn INTO #temp2 FROM #temp
 
while @x<=(SELECT COUNT(*) FROM #temp2)
BEGIN
    IF @x=1
    BEGIN
     INSERT INTO #temp3
     SELECT * FROM #temp2 WHERE rn=@x
    END
    ELSE
    BEGIN
      SELECT @anterior=dato3 FROM #temp3 WHERE rn=@x-1
      SELECT @valor=dato2 FROM #temp2 WHERE rn=@x     
      SET @NEXT=@anterior+@valor
      INSERT INTO #temp3 VALUES (@anterior,@valor,@NEXT,@x)
    END
SET @x=@x+1  
END
 
SELECT * FROM #temp3
DROP TABLE #temp2
DROP TABLE #temp3
 

esto te sirve??