Seeking Sqlite no-op command

Question

Is there a command which I can run to do nothing (or very little) which will never error?

I need something for testing porpoises.

Answer 1

A comment does nothing (but your database driver might complain if there is not command at all):

/* Hello, world! */

Unknown PRAGMA statements are ignored, and do not return anything:

PRAGMA testing_porpoises;

If you need a statement that returns an empty result set, you need a SELECT:

SELECT 0 WHERE 0;

Answer 2

For example a simple constant select could do:

SELECT 1 WHERE 0;