How to shuffle characters in a string?

Question

PostgreSQL

How do I move letters in the end string of a password?

SELECT string_agg(concat(
  substring('ABCDEFGHIJKLMNOPQRSTUVWXYZ', ceil(random() * 26)::integer, 1),
  substring('abcdefghijklmnopqrstuvwxyz', ceil(random() * 26)::integer, 1),
  substring('0123456789', ceil(random() * 10)::integer, 1),
  substring('!#$%&()*+,-./:;<=>[email protected][]^', ceil(random() * 23)::integer, 1)
), '') 
FROM generate_series(1,8);

Answer 1

Well mix it up...

SELECT string_agg(concat(substring('ABCDEFGHIJKLMNOPQRSTUVWXYZ', ceil(random() * 26)::integer, 1),
                         substring('abcdefghijklmnopqrstuvwxyz', ceil(random() * 26)::integer, 1),
                         substring('0123456789', ceil(random() * 10)::integer, 1),
                         substring('!#$%&()*+,-./:;<=>[email protected][]^', ceil(random() * 23)::integer, 1)
                         ),
                  '' ORDER BY RANDOM()
                  ) 
FROM generate_series(1,8);

Answer 2

SELECT string_agg(unnest, '') FROM(

select * FROM (select unnest(string_to_array(string_agg(concat(
  substring('ABCDEFGHIJKLMNOPQRSTUVWXYZ', ceil(random() * 26)::integer, 1),
  substring('abcdefghijklmnopqrstuvwxyz', ceil(random() * 26)::integer, 1),
  substring('0123456789', ceil(random() * 10)::integer, 1),
  substring('!#$%&()*+,-./:;<=>[email protected][]^', ceil(random() * 23)::integer, 1)
), ''), NULL)) FROM generate_series(1,8)) x ORDER BY RANDOM()) as random_chars

Hold on, just don't show this to anyone XD
SQL Fiddle

Answer 3

Your perseverance is impressive:

select string_agg(substring, '') from (
  SELECT 
    substring('ABCDEFGHIJKLMNOPQRSTUVWXYZ', ceil(random() * 26)::integer, 1)
  FROM generate_series(1,12) -- 12 capital letters
  union
  SELECT 
    substring('abcdefghijklmnopqrstuvwxyz', ceil(random() * 26)::integer, 1)
  FROM generate_series(1,12) -- 12 low case letters 
  union
  SELECT 
    substring('0123456789', ceil(random() * 10)::integer, 1)
  FROM generate_series(1,6) -- 6 digits
  union
  SELECT 
    substring('!#$%&()*+,-./:;<=>[email protected][]^', ceil(random() * 23)::integer, 1)
  FROM generate_series(1,2) -- 2 other chars
) seria;

PostgreSQL fiddle