需要T-SQL查询找到所有可能的方法

Question

create table #sample (
    product varchar(100),
    Price float
)

insert into #sample values ('Pen',10)
insert into #sample values ('DVD',29)
insert into #sample values ('Pendrive',45)
insert into #sample values ('Mouse',12.5)
insert into #sample values ('TV',49)

select * from #sample

考虑这种情况…

我有1000美元，我想购买上面列出的东西。

我想花全部钱

因此，我需要一个查询，该查询将给出所有产品中多少单位的价格为1000 $

有什么帮助吗？

Answer 1

这是硬编码的，几乎没有灵活性。我的系统花了2分钟才能运行。但是可能会有所帮助，如果没有，抱歉。fnGenerate_Numbers是一个表函数，它返回参数范围内的整数。
做到这一点的方法。

DECLARE @Max INT,
        @Pens money,
        @Dvds money,
        @Pendrives money,
        @Mouses money,
        @Tvs money

SELECT @Max = 1000,
       @Pens = 10,
       @Dvds = 29,
       @Pendrives = 45,
       @Mouses = 12.5,
       @Tvs = 49


;WITH Results AS
(
    SELECT p.n pens, d.n dvds, pd.n pendrives, m.n mouses, t.n tvs, tot.cost
    FROM fnGenerate_Numbers(0, @Max/@Pens) p -- Pens
        CROSS JOIN fnGenerate_Numbers(0, @Max/@Dvds) d -- DVDs
        CROSS JOIN fnGenerate_Numbers(0, @Max/@Pendrives) pd -- Pendrives
        CROSS JOIN fnGenerate_Numbers(0, @Max/@Mouses) m -- Mouses
        CROSS JOIN fnGenerate_Numbers(0, @Max/@Tvs) t -- Tvs
        CROSS APPLY (SELECT p.n * @Pens + d.n * @Dvds + pd.n * + @Pendrives + m.n * @Mouses + t.n * @Tvs cost) tot
    WHERE tot.cost < @Max
), MaxResults AS
(
    SELECT 
        MAX(pens) pens,
        dvds,
        pendrives,
        mouses,
        tvs
    FROM Results
    GROUP BY
        dvds,
        pendrives,
        mouses,
        tvs
)
SELECT mr.*, r.cost FROM MaxResults mr
    INNER JOIN Results r ON mr.pens = r.pens 
        AND mr.dvds = r.dvds
        AND mr.pendrives = r.pendrives
        AND mr.mouses = r.mouses
        AND mr.tvs = r.tvs
ORDER BY cost