Question

我有一个名为RedMarkSubcategory的表，例如：

+----------------------+--------+-----------+
| RedMarkSubcategoryId |  Name  | IsDeleted |
+----------------------+--------+-----------+
|                    1 | Item 1 |         0 |
|                    2 | Item 2 |         0 |
|                    3 | Item 3 |         0 |
+----------------------+--------+-----------+

我还有另一个名为RedMarkItems的表，其列名为RedMarkSubcategoryId-像这样：

+----------------+-------+-------+-------+
| RedMArkItemsId | Item1 | Item2 | Item3 |
+----------------+-------+-------+-------+
|              1 |     0 |     0 |     0 |
|              2 |     0 |     0 |     0 |
|              3 |     0 |     0 |     0 |
+----------------+-------+-------+-------+

您可以看到创建的列没有空间。我的问题是，有没有办法将这两个表关联起来以获得类似这样的结果？

SELECT 
    [RS].[Name], RI.* 
FROM
    RedMarkSubcategory AS RS
INNER JOIN 
    RedMarkItems AS [RI] ON RS.Name = "RI.columnName" 
WHERE 
    RS.IsDeleted = 0

Answer 1

是的，您可以join表，然后提取值。例如：

SELECT [RS].[Name],
       (CASE WHEN RS.NAME = 'Item 1' THEN RI.item1
             WHEN RS.NAME = 'Item 2' THEN RI.item2
             WHEN RS.NAME = 'Item 3' THEN RI.item3
        END) as ri_value
FROM RedMarkSubcategory RS INNER JOIN
     RedMarkItems RI
     ON RS.Name IN ('Item 1', 'Item 2', 'Item 3')
WHERE RS.IsDeleted = 0

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