Question

假设我有一张物料清单表，如下所示：

+----------+-------------+
| ParentNo | ComponentNo |
+----------+-------------+
| AAA      |         101 |
| AAA      |         102 |
| BBB      |         201 |
| BBB      |         202 |
| CCC      |         101 |
| CCC      |         201 |
| CCC      |         301 |
| DDD      |         101 |
| DDD      |         102 |
+----------+-------------+

我想编写一个查询，找到共享相同组件集的任何父数字。我对输出很灵活，但我最初的想法是它类似于：

+----------+---------+
| ParentNo | Matched |
+----------+---------+
| AAA      | DDD     |
| DDD      | AAA     |
+----------+---------+

如Finding duplicate values in a SQL table中所述，有多种方法可以查找为一个或多个字段共享相同值的单个记录。但是我只想在 all 两个不同父项的组件匹配时返回结果。

我见过的最接近的解决方案是SQL selecting rows where one column's value is common across another criteria column。这不符合我的需要，因为必须提供一组特定的ComponentNo。我试图避免手动输入每个ParentNo的ComponentNo（我正在使用的数据集包含数千万条记录）。

我觉得某种形式的递归查询在这种情况下可能是合适的，但是我的尝试并没有产生任何看起来像是在正确路径上的查询。

Answer 1

您可以使用LISTAGG连接父级的所有组件。然后使用self join检查具有相同组件的父项。

with grouped_comps as (
select parentno, LISTAGG(cast(componentno as varchar(10000)), ',') WITHIN GROUP(ORDER BY componentno) as comp_all
from t
group by parentno)
select g1.parentno,g2.parentno
from grouped_comps g1
join grouped_comps g2 on g1.parentno<>g2.parentno and g1.comp_all=g2.comp_all

Answer 2

尝试类似这样的事情

<unknown>:0: error: no such file or directory: '/Users/trevorjordy/Library/Developer/Xcode/DerivedData/Duelyst_Database-eiwmunfsyfyouhbystikkuvfadfh/Build/Intermediates/Duelyst Database.build/Debug-iphonesimulator/Duelyst Database.build/DerivedSources/CoreDataGenerated/Model/.NewestCardsEntity+CoreDataClass.swift'
<unknown>:0: error: no such file or directory: '/Users/trevorjordy/Library/Developer/Xcode/DerivedData/Duelyst_Database-eiwmunfsyfyouhbystikkuvfadfh/Build/Intermediates/Duelyst Database.build/Debug-iphonesimulator/Duelyst Database.build/DerivedSources/CoreDataGenerated/Model/.NewestCardsEntity+CoreDataProperties.swift'
<unknown>:0: error: no such file or directory: '/Users/trevorjordy/Library/Developer/Xcode/DerivedData/Duelyst_Database-eiwmunfsyfyouhbystikkuvfadfh/Build/Intermediates/Duelyst Database.build/Debug-iphonesimulator/Duelyst Database.build/DerivedSources/CoreDataGenerated/Model/.SetsEntity+CoreDataClass.swift'
<unknown>:0: error: no such file or directory: '/Users/trevorjordy/Library/Developer/Xcode/DerivedData/Duelyst_Database-eiwmunfsyfyouhbystikkuvfadfh/Build/Intermediates/Duelyst Database.build/Debug-iphonesimulator/Duelyst Database.build/DerivedSources/CoreDataGenerated/Model/.SetsEntity+CoreDataProperties.swift'
Command /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swiftc failed with exit code 1

Answer 3

另一种可能性：

with data (bk,komp) as (values
('AAA', 101),('AAA', 102),('BBB', 201),
('BBB', 202),('CCC', 101),('CCC', 201),
('CCC', 301),('DDD', 101),('DDD', 102)
)
select d1.bk,d2.bk
from   data d1
inner  join data d2
on     d1.bk <> d2.bk
group  by d1.bk,d2.bk
having count(distinct d1.komp) = 
       count(case when d1.komp = d2.komp then 1 end)

Answer 4

 SELECT Parent.ParentNo,Child.ParentNo FROM 
 TABLE AS Parent
 LEFT JOIN TABLE as Child
 ON Child.ComponentNo = Parent.ComponentNo
 Where Parent.ParentNo != Child.ParentNo

SQL选择记录，其中一个字段的值与另一个字段的值相似

4 个答案: