单个SELECT语句，用于检索1列的所有可能组合值Oracle

Question

说我有一个专栏：

COLUMN
Bread
Butter
Toast
Jam

我需要一个有效的选择查询，它将返回：

COLUMN
Bread Butter
Bread Toast
Bread Jam
Butter Bread
Butter Toast
Butter Jam
Toast Bread
Toast Butter
Toast Jam
Jam Bread
Jam Butter
Jam Toast

Answer 1

以下查询应该执行您想要的操作，它将表连接到自身并删除与项匹配的行。

SELECT 
      T1.COLUMN || ' ' || T2.COLUMN
FROM
      TABLE T1
JOIN
       TABLE T2 ON T2.COLUMN <> T1.COLUMN

Answer 2

select c1 || ' ' || c2
from 
( select column as c1 from table ),
( select column as c2 from table )
where c1 <> c2 -- this avoids the commented 'jam jam' :)

Answer 3

这不只是一个带有简单过滤器的cross join吗？

with [Data] as (
         select *
         from (values
             (N'Bread')
           , (N'Butter')
           , (N'Toast')
           , (N'Jam')
         ) as a ([Value])
     )
select a.[Value] + N' ' + b.[Value] as [Value]
from [Data] as a
cross join [Data] as b
where a.[Value] <> b.[Value];