Natural ordering of migrations' versions using MySQL and Postgre

version_natural_sorting_mysql.sql

SELECT 
  SUBSTRING_INDEX(number, '.', 1) AS FIRST_INT, 
  SUBSTRING_INDEX(SUBSTRING_INDEX(number, '.', 2), '.', -1) AS SECOND_INT, 
  SUBSTRING_INDEX(number, '.', -1) AS THIRD_INT,
  number as VERSION, 
  description as TITLE 
FROM _version 
ORDER BY
  LENGTH(SUBSTRING_INDEX(number, '.', 1)) DESC,
  SUBSTRING_INDEX(number, '.', 1) DESC, 
  LENGTH(SUBSTRING_INDEX(SUBSTRING_INDEX(number, '.', 2), '.', -1)) DESC,
  SUBSTRING_INDEX(SUBSTRING_INDEX(number, '.', 2), '.', -1) DESC, 
  LENGTH(SUBSTRING_INDEX(number, '.', -1)) DESC,
  SUBSTRING_INDEX(number, '.', -1) DESC

version_natural_sorting_postgresql.sql

SELECT 
  number as VERSION, 
  split_part(number, '.', 1) AS FIRST_INT,
  split_part(number, '.', 2) AS SECOND_INT,
  split_part(number, '.', 3) AS THIRD_INT,
  description as TITLE 
FROM _version 
ORDER BY
  split_part(number, '.', 1)::int DESC
  split_part(number, '.', 2)::int DESC
  split_part(number, '.', 3)::int DESC

Natural vs Alphabetical sort order

Normally, the default sorting order used is the numerical/alphabetical one. Postgresql can do much more because it's possible to cast string into integers and vice versa.

About the natural sorting take a look at this coding horror post

For PgSQL see also this SO answer: https://stackoverflow.com/a/9173594/1977778