On Wed, Dec 11, 2024 at 11:46 AM Marcos Pegoraro <mar...@f10.com.br> wrote:
> Em ter., 10 de dez. de 2024 às 20:00, David G. Johnston < >> david.g.johns...@gmail.com> escreveu: >> > > Section nullvalues-filtering you are showing filtering with equal and not > equal. Wouldn't it be better if you show just one of them and the other > using DISTINCT FROM, which would get different results ? > > I'm demonstrating the sentence written there - A WHERE clause that evaluates to a null value for a given row will exclude that row. While I can do that with a single example my intent here was to also show that if one writes seemingly mutually exclusive expressions in a where clause it is possible neither expression will find a row, in this case with id=2. "p OR !p" again. I'll give this some more thought though. In any case I do need to add a few more words framing up the examples. Probably pointing back to the cardinal rule sub-section. David J.
