Question

我有这两个查询几乎可以提供我需要的数据：

SELECT  Products.ItemID, Products.ItemID + '-' + ModifierListItems.ItemID AS SizeItemID
FROM         ModifierLists INNER JOIN
                      ProductModifierLists ON ModifierLists.ModifierListID = ProductModifierLists.ModifierListID INNER JOIN
                      ModifierListItems ON ModifierLists.ModifierListID = ModifierListItems.ModifierListID INNER JOIN
                      Products ON ProductModifierLists.ItemID = Products.ItemID AND ProductModifierLists.ManufacturerID = Products.ManufacturerID
WHERE     (Products.ManufacturerID = 262) AND ModifierListName='Size'
ORDER BY Products.ItemID

SELECT  Products.ItemID, ModifierListItems.ItemID AS ColorItemID
FROM         ModifierLists INNER JOIN
                      ProductModifierLists ON ModifierLists.ModifierListID = ProductModifierLists.ModifierListID INNER JOIN
                      ModifierListItems ON ModifierLists.ModifierListID = ModifierListItems.ModifierListID INNER JOIN
                      Products ON ProductModifierLists.ItemID = Products.ItemID AND ProductModifierLists.ManufacturerID = Products.ManufacturerID
WHERE     (Products.ManufacturerID = 262) AND ModifierListName='Color'
ORDER BY Products.ItemID

我正在寻找的最终输出是与ItemID上连接的ColorItemID连接的SizeItemID。

2个查询的示例结果：

ItemID    SizeItemID
-------   ----------
A          A-S
A          A-M
B          B-M
B          B-L

ItemID     ColorItemID
-------    -----------
A            BLK
A            WHT
B            BLK
B            WHT
B            GRN

我正在寻找的结果如下：

FinalItemID
-----------
A-S-BLK
A-S-WHT
A-M-BLK
A-M-WHT
B-M-BLK
B-M-WHT
B-M-GRN
B-L-BLK
B-L-WHT
B-L-GRN

Answer 1

您可以接受两个查询并将它们连接在一起以构建最终值。

在以下查询中，我还在表名上使用别名。许多人发现有意义的别名比长表名更容易阅读：

with tsize as (
     SELECT p.ItemID,
            p.ItemID + '-' + mli.ItemID AS SizeItemID
     FROM ModifierLists ml INNER JOIN
           ProductModifierLists pml 
           ON ml.ModifierListID = pml.ModifierListID INNER JOIN
           ModifierListItems mli
           ON ml.ModifierListID = mli.ModifierListID INNER JOIN
           Products p
           ON pml.ItemID = Products.ItemID AND
              pml.ManufacturerID = p.ManufacturerID
     WHERE (p.ManufacturerID = 262) AND ModifierListName='Size'
    ),
     tcolor as (
     SELECT  p.ItemID, mli.ItemID AS ColorItemID
     FROM ModifierLists moli INNER JOIN
          ProductModifierLists pml
          ON ml.ModifierListID = pml.ModifierListID INNER JOIN
          ModifierListItems mli
          ON ml.ModifierListID = mli.ModifierListID INNER JOIN
          Products p
          ON pml.ItemID = Products.ItemID AND
             pml.ManufacturerID = p.ManufacturerID
     WHERE     (Products.ManufacturerID = 262) AND ModifierListName='Color'
    )
select SizeItemID+'-'+ColorItemID
from tsize join tcolor
    on tsize.itemid = tcolor.ItemID

Answer 2

嗯，最干净的方法是将每个查询放入自己的视图中。它也可以帮助你理解你做得更好。因此，如果我们接受查询并创建了视图：

CREATE VIEW v_ProductSize
AS
SELECT  Products.ItemID, Products.ItemID + '-' + ModifierListItems.ItemID AS SizeItemID
FROM         ModifierLists INNER JOIN
                      ProductModifierLists ON ModifierLists.ModifierListID = ProductModifierLists.ModifierListID INNER JOIN
                      ModifierListItems ON ModifierLists.ModifierListID = ModifierListItems.ModifierListID INNER JOIN
                      Products ON ProductModifierLists.ItemID = Products.ItemID AND ProductModifierLists.ManufacturerID = Products.ManufacturerID
WHERE     (Products.ManufacturerID = 262) AND ModifierListName='Size'
ORDER BY Products.ItemID


CREATE VIEW v_ProductColor
AS
SELECT  Products.ItemID, ModifierListItems.ItemID AS ColorItemID
FROM         ModifierLists INNER JOIN
                      ProductModifierLists ON ModifierLists.ModifierListID = ProductModifierLists.ModifierListID INNER JOIN
                      ModifierListItems ON ModifierLists.ModifierListID = ModifierListItems.ModifierListID INNER JOIN
                      Products ON ProductModifierLists.ItemID = Products.ItemID AND ProductModifierLists.ManufacturerID = Products.ManufacturerID
WHERE     (Products.ManufacturerID = 262) AND ModifierListName='Color'
ORDER BY Products.ItemID

然后你有两个可以正常使用的简单视图，对吗？所以你的查询将是：

SELECT ps.SizeItemID +' - '+ pc.ColorItemID FROM v_ProductSize ps JOIN v_ProductColor pc ON ps.ItemID = pc.ItemID

看看它是如何工作的？你只是像任何其他表一样进行正常连接。现在，假设您不想创建视图，或者由于某种原因没有权限。您可以跳过视图部件本身，并使用子查询。您只需将参数替换为视图，查询本身就在括号中。

所以它看起来像这样：

SELECT ps.SizeItemID + '-' + pc.ColorItemID
FROM (
        SELECT  Products.ItemID, Products.ItemID + '-' + ModifierListItems.ItemID AS SizeItemID
         FROM         ModifierLists INNER JOIN
                               ProductModifierLists ON ModifierLists.ModifierListID = ProductModifierLists.ModifierListID INNER JOIN
                               ModifierListItems ON ModifierLists.ModifierListID = ModifierListItems.ModifierListID INNER JOIN
                               Products ON ProductModifierLists.ItemID = Products.ItemID AND ProductModifierLists.ManufacturerID = Products.ManufacturerID
         WHERE     (Products.ManufacturerID = 262) AND ModifierListName='Size'
         ORDER BY Products.ItemID
) ps
JOIN 
     (    SELECT  Products.ItemID, ModifierListItems.ItemID AS ColorItemID
    FROM         ModifierLists INNER JOIN
                          ProductModifierLists ON ModifierLists.ModifierListID = ProductModifierLists.ModifierListID INNER JOIN
                          ModifierListItems ON ModifierLists.ModifierListID = ModifierListItems.ModifierListID INNER JOIN
                          Products ON ProductModifierLists.ItemID = Products.ItemID AND ProductModifierLists.ManufacturerID = Products.ManufacturerID
    WHERE     (Products.ManufacturerID = 262) AND ModifierListName='Color'
    ORDER BY Products.ItemID
) pc ON ps.itemID=pc.ItemID

现在......所有这些，并且随着我的咖啡最终开始，您可以通过一行修改大大简化查询：

SELECT  Products.ItemID, Products.ItemID + '-' + colors.ItemID + '-' + sizes.ItemID AS SizeColorItemID
FROM         ModifierLists 
INNER JOIN  ProductModifierLists ON ModifierLists.ModifierListID = ProductModifierLists.ModifierListID 
INNER JOIN ModifierListItems sizes ON ModifierLists.ModifierListID = ModifierListItems.ModifierListID 
                                    --Put modifier list name in join clause
                                    AND ModifierListName='Size'
INNER JOIN ModifierListItems colors ON ModifierLists.ModifierListID = ModifierListItems.ModifierListID
                                    --same here, but for color
                                    AND ModifierListName = 'Color'
INNER JOIN Products ON ProductModifierLists.ItemID = Products.ItemID 
                    AND ProductModifierLists.ManufacturerID = Products.ManufacturerID               
WHERE     (Products.ManufacturerID = 262)  --Remove modifierlistitem here so you can use it in the join clauses
ORDER BY Products.ItemID

因为我们真的在原始查询中提取相同的信息，只有一个不同的条件......我们可以将modifierlistitem.name移动到join子句中，然后再次使用不同的条件连接到同一个表。然后我们根据我们使用的条件（大小，颜色）对表进行别名。这样你就可以引用别名并拉出正确的项ID，并立即将它们连接起来。

Answer 3

试试这个：

您只需要将两个查询作为派生表并加入ItemID

Select a.SizeItemID+'-'+b.ColorItemID as FinalItemID
FROM
    (SELECT  Products.ItemID, Products.ItemID + '-' + ModifierListItems.ItemID AS SizeItemID
    FROM         ModifierLists INNER JOIN
                          ProductModifierLists ON ModifierLists.ModifierListID = ProductModifierLists.ModifierListID INNER JOIN
                          ModifierListItems ON ModifierLists.ModifierListID = ModifierListItems.ModifierListID INNER JOIN
                          Products ON ProductModifierLists.ItemID = Products.ItemID AND ProductModifierLists.ManufacturerID = Products.ManufacturerID
    WHERE     (Products.ManufacturerID = 262) AND ModifierListName='Size'
    )a
JOIN
    (SELECT  Products.ItemID, ModifierListItems.ItemID AS ColorItemID
    FROM         ModifierLists INNER JOIN
                          ProductModifierLists ON ModifierLists.ModifierListID = ProductModifierLists.ModifierListID INNER JOIN
                          ModifierListItems ON ModifierLists.ModifierListID = ModifierListItems.ModifierListID INNER JOIN
                          Products ON ProductModifierLists.ItemID = Products.ItemID AND ProductModifierLists.ManufacturerID = Products.ManufacturerID
    WHERE     (Products.ManufacturerID = 262) AND ModifierListName='Color'
    )b
on a.ItemID=b.ItemID
ORDER BY  a.FinalItemID

加入2个SQL查询并连接结果？

3 个答案: