jdev - 2024-05-04

0 day since SQL got me

SELECT * FROM table WHERE key is not NULL -> returns records SELECT * FROM table WHERE key not in (NULL) -> returns no records

that looks like the kind of stuff which is not just non-obvious, but will also differ between implementations.

probably stuff with NULL often differs between implementations

example indexes with NULL values in it

indeed

but the nice thing about sql is, it doesnt matter which question you have, the answer is a search away

unless you're on oracle

That one seems likely to be true on most implementations. Since IN is effectively a version of = and =NULL is usually false

Question is when is this useful