Intentionally produce Errors - Mailing list pgsql-general

Hi,

this is sort of a silly question, but: what's the proper way to
intentionally generate an error? I'm writing tests for pyPgSQL and want
to check it's error handling. Currently, I'm using:

SELECT "THIS PRODUCES AN SQL ERROR";

Is there any better way to generate errors? Probably even generating
specific errors given?

Regards

Markus