Useful SQL request

SQL Cheatsheet

-- select the nth row of a table
-- from http://stackoverflow.com/questions/16568/how-to-select-the-nth-row-in-a-sql-database-table
SELECT * FROM (
  SELECT
    ROW_NUMBER() OVER (ORDER BY key ASC) AS rownumber,
    columns
  FROM tablename
  WHERE condition
) AS foo
WHERE rownumber = n