How to generate a permutations or combinations of n rows in m columns?

Question

Does anyone know how to create a table with m columns from table of n rows where the values in columns of each row represent a different combination or permutation of values

Answer 1

Combinations:

SELECT T1.x, T2.x
FROM your_table T1
JOIN your_table T2
ON T1.x < T2.x

Permutations:

SELECT T1.x, T2.x
FROM your_table T1
JOIN your_table T2
ON T1.x != T2.x

I am assuming that the values in the original table are unique.

To generalize for larger values of m you need to add more joins.