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Well, it would be if testing x = y produced sane results where one of those is null.

I understand why SQL chooses to treat null as unknown for comparison, but I hate it with every fibre of my being and wish SQL dialects would join the 21st century and let me define alternate concepts of nullity like we can with modern type systems.

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Ideally you'd want your RDBMS to refuse to compile tests like x = y in cases where either x or y could be null. You would have to explicitly handle nulls in boolean statements.

That would be sensible if SQL dialects usually offered a sane comparison that returns true/false reasonably for null comparisons. Since they don't, and = is the only available equality test, I'm going to stick to my original point that null comparison in SQL is dumb and wrong for 99% of use-cases and compiler warnings would be solving the wrong problem.

MySql, Postgres, and Vertica, at least, all support <=> as an operator that treats NULL as an ordinary, distinct value.

I've been working on a linter for SQL - that's probably not a bad rule to toss in the mix...

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