如何在sqlite一列的组合?

Question

我有这个sqlite列:

USA
Russia
Japan

和我需要像这样有两列:

USA Russia
USA Japan
Russia USA
Russia Japan
Japan USA
Japan Russia

我该怎么做呢?

Answer 1

Just join

select  t1.country, t2.country
from myTable as t1
join myTable as t2 on t1.country != t2.country

Answer 2

您需要根据列的不相等对表进行自连接:

SELECT t1.col AS column1, 
t2.col AS column2
FROM tablename t1 INNER JOIN tablename t2
ON t2.col <> t1.col;