Calculate Permutations

Hey,

I'm looking forward for an algorithm for permutations with repetition.

My idea was to fill a table with the different elements to choose from e.g A;B;C and then make a combination of CROSS JOIN. For example like this, if you would select 3 times.

SELECT * FROM "tab1" CROSS JOIN "tab1" CROSS JOIN "tab1";

This works fine so far. Now I wanted to put this in a procedure where the number of selections is the input parameter.

CREATE PROCEDURE "TEST_SYSTEM"."permutation" (

IN numberSelections INT)

  LANGUAGE SQLSCRIPT

  SQL SECURITY INVOKER

  DEFAULT SCHEMA TEST_SYSTEM

  AS

BEGIN

DECLARE loop_index INT := 1;

leftTab = SELECT "VAR1" AS "left" FROM "tab1";

WHILE loop_index < numberSelections DO

rightTab = SELECT "VAR1" AS "right" FROM "tab1";

leftTab = SELECT * FROM :leftTab CROSS JOIN :rightTab;

loop_index = :loop_index - 1;

END WHILE;

END;