如何找到具有类似组件的产品？

Question

我试图找到其中至少有75%+类似组件的物品,我们有数千种产品.我的表有2列,Item和Component.例:

+------+-----------+
| Item | Component |
+------+-----------+
| AAA  | screw     |
| AAA  | metal     |
| AAA  | bar       |
| AAA  | nut       |
| ABC  | screw     |
| ABC  | metal     |
| ABC  | bar       |
| CAA  | nut       |
| CAA  | cap       |
+------+-----------+

最终的结果我想获得3列.项目,项目2和百分比相似.所以看起来像:

+------+-------+-------------------+
| Item | Item2 | PercentageSimilar |
+------+-------+-------------------+
| AAA  | ABC   | 75%               |
| AAA  | CAA   | 25%               |
| ABC  | AAA   | 100%              |
| ABC  | CAA   | 0%                |
| CAA  | AAA   | 50%               |
| CAA  | ABC   | 0%                |
+------+-------+-------------------+

这可能与SQL有关吗？

Answer 1

您可以使用a self join来执行此操作.

select t1.item,t2.item
,100.*count(case when t1.component=t2.component then 1 end)
 /count(distinct t1.component) as pct_similar
from t t1
join t t2 on t1.item<>t2.item
group by t1.item,t2.item