The sample.pgn PGN file

The PGN file sample.pgn download is a collection of approximately 200 endgame studies selected from the Heijden database. The full Heijden database contains more than 85000 endgame studies, and we recommend it for use with CQL (or, for that matter, for anyone interested in endgame studies).

The studies in sample.pgn were selected so that each of the CQL examples would find some matches when run against the database. Although there are many interesting studies among the 200 studies here, many of them were programmatically selected to make the examples all work - this is not intended as a "best studies" collection.

To use the sample.pgn database on a cql file named foo.cql, invoke cql using this syntax:

  cql -i sample.pgn foo.cql

This will create a file named foo-out.pgn located in the directory from which cql was run.

The sample.pgn file also contains one problem, to illustrate the use of CQL on a problem theme.