减去两个和

Question

请假设这是DB fiddle。

-- INVENTORY TABLE DECLARATION AND DATA INSERTION
DECLARE @COLORSIZEQTYS TABLE(ITEID int, COLORCODE varchar(15), QTYMODE smallint, SIZE4 float, SIZE5 float, SIZE6 float, SIZE7 float);

INSERT @COLORSIZEQTYS(ITEID, COLORCODE, QTYMODE, SIZE4, SIZE5, SIZE6, SIZE7) VALUES(5594, 'Grey',  1, -2, -1,  3,  4);
INSERT @COLORSIZEQTYS(ITEID, COLORCODE, QTYMODE, SIZE4, SIZE5, SIZE6, SIZE7) VALUES(5594, 'Red',   1,  2,  5,  5,  2);
INSERT @COLORSIZEQTYS(ITEID, COLORCODE, QTYMODE, SIZE4, SIZE5, SIZE6, SIZE7) VALUES(5594, 'Green', 1,  2,  2,  4, -1);
INSERT @COLORSIZEQTYS(ITEID, COLORCODE, QTYMODE, SIZE4, SIZE5, SIZE6, SIZE7) VALUES(5594, 'Grey',  0,  2,  0, -1,  1);
INSERT @COLORSIZEQTYS(ITEID, COLORCODE, QTYMODE, SIZE4, SIZE5, SIZE6, SIZE7) VALUES(5594, 'White', 0,  2,  3,  3,  0);
INSERT @COLORSIZEQTYS(ITEID, COLORCODE, QTYMODE, SIZE4, SIZE5, SIZE6, SIZE7) VALUES(5594, 'Blue',  1, -1,  6,  0,  3);
INSERT @COLORSIZEQTYS(ITEID, COLORCODE, QTYMODE, SIZE4, SIZE5, SIZE6, SIZE7) VALUES(5594, 'Grey',  1,  7,  2, -1,  4);
INSERT @COLORSIZEQTYS(ITEID, COLORCODE, QTYMODE, SIZE4, SIZE5, SIZE6, SIZE7) VALUES(5594, 'Grey',  1,  1,  0, -1, -1);

-- PURCHASES TABLE DECLARATION AND DATA INSERTION
DECLARE @STORECOLORSIZEEST TABLE(ID int, ITEID int, COLORCODE varchar(15), SIZE4 float, SIZE5 float, SIZE6 float, SIZE7 float);

INSERT @STORECOLORSIZEEST(ID, ITEID, COLORCODE, SIZE4, SIZE5, SIZE6, SIZE7) VALUES(1703, 5594, 'Grey', 0, 1, 0, 1);
INSERT @STORECOLORSIZEEST(ID, ITEID, COLORCODE, SIZE4, SIZE5, SIZE6, SIZE7) VALUES(1704, 6811, 'Red',  0, 1, 0, 1);
INSERT @STORECOLORSIZEEST(ID, ITEID, COLORCODE, SIZE4, SIZE5, SIZE6, SIZE7) VALUES(1706, 5594, 'Grey', 0, 1, 1, 1);
INSERT @STORECOLORSIZEEST(ID, ITEID, COLORCODE, SIZE4, SIZE5, SIZE6, SIZE7) VALUES(1707, 5594, 'Grey', 1, 1, 0, 1);
INSERT @STORECOLORSIZEEST(ID, ITEID, COLORCODE, SIZE4, SIZE5, SIZE6, SIZE7) VALUES(1709, 8372, 'Blue', 0, 1, 0, 1);
INSERT @STORECOLORSIZEEST(ID, ITEID, COLORCODE, SIZE4, SIZE5, SIZE6, SIZE7) VALUES(1712, 5594, 'Grey', 0, 0, 1, 1);

-- QUERY SUMMING INVENTORY ROWS
SELECT SUM(SIZE4) AS QTY4,
       SUM(SIZE5) AS QTY5,
       SUM(SIZE6) AS QTY6,
       SUM(SIZE7) AS QTY7
FROM @COLORSIZEQTYS
WHERE ITEID = 5594
AND COLORCODE = 'Grey'
AND QTYMODE = 1

-- QUERY SUMMING INVENTORY ROWS AND ZERO-ING NEGATIVE VALUES
SELECT SUM(CASE WHEN SIZE4 < 0 THEN 0 ELSE SIZE4 END) AS QTY4,
       SUM(CASE WHEN SIZE5 < 0 THEN 0 ELSE SIZE5 END) AS QTY5,
       SUM(CASE WHEN SIZE6 < 0 THEN 0 ELSE SIZE6 END) AS QTY6,
       SUM(CASE WHEN SIZE7 < 0 THEN 0 ELSE SIZE7 END) AS QTY7
FROM @COLORSIZEQTYS
WHERE ITEID = 5594
AND COLORCODE = 'Grey'
AND QTYMODE = 1

-- QUERY SUMMING PURCHASE ROWS
SELECT SUM(SIZE4) AS RSV4,
       SUM(SIZE5) AS RSV5,
       SUM(SIZE6) AS RSV6,
       SUM(SIZE7) AS RSV7
FROM @STORECOLORSIZEEST
WHERE ITEID = 5594
AND COLORCODE = 'Grey'

-- SUBTRACTING THE TWO SUMS TO FIND THE FINAL INVENTORY QUANTITIES - CLEARLY THIS DOESN'T WORK
SELECT (SUM(CASE WHEN inv.SIZE4 < 0 THEN 0 ELSE inv.SIZE4 END) - SUM(pcs.SIZE4)) AS TOT4,
       (SUM(CASE WHEN inv.SIZE5 < 0 THEN 0 ELSE inv.SIZE5 END) - SUM(pcs.SIZE5)) AS TOT5,
       (SUM(CASE WHEN inv.SIZE6 < 0 THEN 0 ELSE inv.SIZE6 END) - SUM(pcs.SIZE6)) AS TOT6,
       (SUM(CASE WHEN inv.SIZE7 < 0 THEN 0 ELSE inv.SIZE7 END) - SUM(pcs.SIZE7)) AS TOT7
FROM @COLORSIZEQTYS AS inv
INNER JOIN @STORECOLORSIZEEST AS pcs ON pcs.ITEID = inv.ITEID AND pcs.COLORCODE = inv.COLORCODE
WHERE inv.ITEID = 5594 AND inv.COLORCODE = 'Grey' AND inv.QTYMODE = 1

所以我有两张表，一张是产品库存及其每种尺寸的数量，另一张是产品的采购行以及每种尺寸的购买数量。

我想计算每种尺寸的最终新库存数量，将超卖尺寸归零（这种超卖有时会发生，因为系统运营商未能登记某些销售）。

无论如何，对于小提琴的例子，总数应该像

TOT4	TOT5	TOT6	TOT7
7	-1	1	4

在我们将超卖的归零后，它们应该变成

TOT4	TOT5	TOT6	TOT7
7	0	1	4

在我的小提琴中，我试图计算两个和的减法，但我不知道我做错了什么，因为它计算的结果完全不同！我知道我已经很接近了，但我无法让它发挥作用。

有人可以帮我纠正最后的查询吗？提前致谢。

Answer 1

你很亲密。

您的查询中的错误是所有相关的个人购买行都连接到所有相关的个人库存行，其中“相关”是指灰色 5594 的。理解我的意思的最简单方法是运行最终查询，但执行 select * 而不是求和。

解决方案是确保先求和，然后将购买结果加入库存结果，然后进行减法（而不是在求和之前加入）。

当我们这样做时，我们可以交叉连接，因为在我们过滤到我们想要的颜色和项目并获取总和后，将只有一行用于购买，而一行用于库存。

为简单起见，我删除了与查询无关的示例数据。

此外，我还提供了完整的设置和解决方案，因为我认为您也可以从中学到一些东西。请注意，例如，您不必为每个值行执行单独的插入语句。您可以在每个插入的行后添加一个逗号。这使得设置更易于阅读。

-- INVENTORY TABLE DECLARATION AND DATA INSERTION
declare @COLORSIZEQTYS TABLE
(
   ITEID     int,
   COLORCODE varchar(15),
   QTYMODE   smallint,
   SIZE4     float,
   SIZE5     float,
   SIZE6     float,
   SIZE7     float
);

-- PURCHASES TABLE DECLARATION AND DATA INSERTION
declare @STORECOLORSIZEEST TABLE
(
   ID        int,
   ITEID     int,
   COLORCODE varchar(15),
   SIZE4     float,
   SIZE5     float,
   SIZE6     float,
   SIZE7     float
);

insert @COLORSIZEQTYS(ITEID, COLORCODE, QTYMODE, SIZE4, SIZE5, SIZE6, SIZE7)
values
(5594, 'Grey', 1,     -2, -1, 3, 4),
(5594, 'Grey', 0,     2, 0, -1, 1),
(5594, 'Grey', 1,     7, 2, -1, 4),
(5594, 'Grey', 1,     1, 0, -1, -1);

insert @STORECOLORSIZEEST(ID, ITEID, COLORCODE, SIZE4, SIZE5, SIZE6, SIZE7)
values
(1703, 5594, 'Grey',  0, 1, 0, 1),
(1706, 5594, 'Grey',  0, 1, 1, 1),
(1707, 5594, 'Grey',  1, 1, 0, 1),
(1712, 5594, 'Grey',  0, 0, 1, 1);

with zeroedinv as
(
   select   SUM(case when SIZE4 < 0 then 0 else SIZE4 end) as QTY4,
            SUM(case when SIZE5 < 0 then 0 else SIZE5 end) as QTY5,
            SUM(case when SIZE6 < 0 then 0 else SIZE6 end) as QTY6,
            SUM(case when SIZE7 < 0 then 0 else SIZE7 end) as QTY7
   from     @COLORSIZEQTYS
   where    ITEID = 5594
            and COLORCODE = 'Grey'
            and QTYMODE = 1
),
purchases as
(
   select   SUM(SIZE4) as RSV4,
            SUM(SIZE5) as RSV5,
            SUM(SIZE6) as RSV6,
            SUM(SIZE7) as RSV7
   from     @STORECOLORSIZEEST
   where    ITEID = 5594
            and COLORCODE = 'Grey'
)
select      totl4 = iif(qty4 - rsv4 < 0, 0, qty4 - rsv4),
            totl5 = iif(qty5 - rsv5 < 0, 0, qty5 - rsv5),
            totl6 = iif(qty6 - rsv6 < 0, 0, qty6 - rsv6),
            totl7 = iif(qty7 - rsv7 < 0, 0, qty7 - rsv7)
from        zeroedinv   
cross join  purchases