DECLARE @tb TABLE([date] datetime, [innum] int, [outnum] int)
INSERT INTO @tb([date],[innum],[outnum])
SELECT '2006-1-1', 50, 30
UNION ALL SELECT '2006-1-2', 100, 40
UNION ALL SELECT '2006-1-3', 0, 80
SELECT [date],[innum],[outnum],0 AS jc INTO #T FROM @tb ORDER BY [DATE]
DECLARE @JC INT
SET @JC = 200
UPDATE #T SET @JC = @JC + innum - outnum, jc = @jc
select * from #T