Sql 先进先出计算积分

先建表，插入测试数据

--正积分表
CREATE table tb1
(
    [memberId] [nvarchar](50) NOT NULL,
    [pointProduceTime] [nvarchar](50) NOT NULL,
    [type] [nvarchar](50) NULL,
    [point] [int] NULL
)
INSERT INTO tb1 VALUES ('','2017-02-06 00:00:00','',360)
INSERT INTO tb1 VALUES ('','2017-03-17 00:00:00','',930)
INSERT INTO tb1 VALUES ('','2017-03-19 00:00:00','',890)
INSERT INTO tb1 VALUES ('','2017-06-09 21:52:14','',700)
INSERT INTO tb1 VALUES ('','2017-08-28 22:26:12','',1090)
INSERT INTO tb1 VALUES ('','2017-10-23 21:16:29','',1330)

--负积分表
CREATE table tb2
(
    [memberId] [nvarchar](50) NOT NULL,
    [pointProduceTime] [nvarchar](50) NOT NULL,
    [type] [nvarchar](50) NULL,
    [point] [int] NULL
)
INSERT INTO tb2 VALUES ('','2017-09-23 21:04:50','',-1090)
INSERT INTO tb2 VALUES ('','2017-11-10 12:56:21','',-2500)

表tb1：

表tb2：

在不知道每次需要扣减多少积分的情况下，需使用游标遍历数据

--正积分
SELECT IDENTITY(INT,1,1) as id,memberId,pointProduceTime,type,point,point as lesspoint
INTO #tb1
FROM tb1

--负积分
SELECT IDENTITY(INT,1,1) as id,memberId,pointProduceTime,type,point
INTO #tb2
FROM tb2

declare @inid int
declare @innum int
declare @indate date
declare @outid int
declare @outnum int
declare @outdate date
DECLARE @lessnum int
--负积分游标
declare xrxc_cursorf cursor
for
select id,pointProduceTime,point from #tb2 order by pointProduceTime
open xrxc_cursorf
fetch next from xrxc_cursorf into @outid,@outdate,@outnum --遍历每行数据
WHILE @@FETCH_STATUS=0
BEGIN
     --正积分游标
    declare xrxc_cursorz cursor
    for
    select id,pointProduceTime,point,lesspoint from #tb1 where lesspoint>0 order by pointProduceTime
    open xrxc_cursorz
    fetch next from xrxc_cursorz into @inid,@indate,@innum,@lessnum --遍历每行数据
    WHILE @@FETCH_STATUS=0
    BEGIN
        --方法参考一
        IF @outnum<=0
            begin
                IF @innum >= @outnum*-1
                    begin
                        update #tb1 SET lesspoint=@outnum+@innum where id=@inid
                    end
                else
                    begin
                        update #tb1 SET lesspoint=0 where id=@inid
                    end

                SET @outnum = @outnum+@lessnum
            end
        else
            update #tb1 SET lesspoint=@lessnum where id=@inid
        fetch next from xrxc_cursorz into @inid,@indate,@innum,@lessnum

        /*
　　　　--方法参考二
        set @outnum=@outnum+@lessnum
        IF @outnum<=0
            begin
                update #tb1 SET lesspoint=0 where id=@inid
            end
        else
            begin
                IF @outnum<@innum
                BEGIN
                    update #tb1 SET lesspoint=@outnum where id=@inid
                end
            end
        fetch next from xrxc_cursorz into @inid,@indate,@innum,@lessnum
　　　　*/

    END
    close xrxc_cursorz
    deallocate xrxc_cursorz
    fetch next from xrxc_cursorf into @outid,@outdate,@outnum
END
close xrxc_cursorf
deallocate xrxc_cursorf
select * from #tb1
select * from #tb2 

DROP TABLE #tb1
DROP TABLE #tb2

结果表：