pá 29. 8. 2025 v 18:51 odesílatel Joel Jacobson <j...@compiler.org> napsal:
> On Fri, Aug 29, 2025, at 18:17, Pavel Stehule wrote: > >> > >> I am not too serious now, I am just playing (and I remember this > discussion many times). We can "theoretically" introduce new keyword > `EXACT`, that can specify so any DML or SELECT can process or returns just > one row (or with other clause zero rows) > >> > >> EXACT ONE SELECT id FROM tab WHERE id = 1; > >> EXACT ONE UPDATE ... > >> EXACT ONE DELETE ... > >> EXACT ONE OR NONE SELECT ... > > > > or > > > > EXACT NONE SELECT ... > > That would work, but I think I prefer CHECK DIAGNOSTICS (ROW_COUNT = 1), > feels a bit more SQL-idiomatic, since there seems to already be a > ROW_COUNT, and there is the concept of DIAGNOSTICS already, and CHECK > feels natural. > > I can also imagine ROW_COUNT with other values than 1 could be useful, > e.g. ROW_COUNT = 2 to enforce inserting two transactions in a > double-entry bookkeeping system. > > In the meantime, maybe we want to add a catalog function > nonnull(anyelement) -> anyelement that throws an error if the input is > NULL? Seems like a function that could be useful in general. > Attached a small patch that adds such a function. > +1 Orafce introduces https://github.com/orafce/orafce: PLUnit <https://github.com/orafce/orafce#plunit> This unit contains some assert functions. - plunit.assert_true(bool [, varchar]) - Asserts that the condition is true. - plunit.assert_false(bool [, varchar]) - Asserts that the condition is false. - plunit.assert_null(anyelement [, varchar]) - Asserts that the actual is null. - plunit.assert_not_null(anyelement [, varchar]) - Asserts that the actual isn’t null. - plunit.assert_equals(anyelement, anyelement [, double precision] [, varchar]) - Asserts that expected and actual are equal. - plunit.assert_not_equals(anyelement, anyelement [, double precision] [, varchar]) - Asserts that expected and actual are equal. - plunit.fail([varchar]) - Fail can be used to cause a test procedure to fail immediately using the supplied message. and for your case some aggregate functions can be nice too like count_one, count_zero, count_one_zero, count_number, ... Regards Pavel > > /Joel
