SQLPP

SQLPP is a simplistic SQL parser and pretty-printer.

require 'sqlpp'

sql = "..."
ast = SQLPP::Parser.parse(sql)

puts SQLPP::Formatter.new.format(ast)

# or, to wrap projection lists...
puts SQLPP::Formatter.new(projections: :wrap).format(ast)

Or, you can use the included bin/sqlpp script to format SQL via STDIN:

$ sqlpp -h
SQLPP (SQL Pretty Printer)

Usage: sqlpp -h -? -wp < SQL

 -h or -?: this list of options
 -wp: wrap the projection lists

$ sqlpp -wp < query.sql
...

The formatter is not particularly sophisticated, and is optimized primarily for displaying queries with deeply nested subselects. The major query components (FROM, WHERE, GROUP BY, and ORDER BY) are printed on separate lines, with subselects indented.

SELECT a, b, sum(c)
FROM (
  SELECT d, e, f
  FROM (
    SELECT g, h, i
    FROM table
    WHERE id IN (1, 2, 3)
  ) a
  WHERE a.e = 5
  OR a.e = 7
) b
WHERE b.c > 5
GROUP BY a, b
ORDER BY a ASC, b DESC

This implementation is far, far, far from complete. It currently accepts only SELECT statements, and even then will only recognize a subset of the valid SQL syntax. That said, it should be a pretty big subset. It's done well enough for what I've needed it for.

If, however, you find that it doesn't recognize some syntax that you need, pull requests would be appreciated!

MIT. See MIT-LICENSE.

Jamis Buck (jamis@jamisbuck.org)