I disagree. It is not at all a design mistake in sql. You can have or forbid null values in tables. And you need that for many things. It is properly designed.

I disagree. It is not at all a design mistake in sql. You can have or forbid null values in tables. And you need that for many things. It is properly designed. Rust or functional languages show you do not generally need null references, you have options instead. It is completely different. Null in C or C++ is much more a very costly misstake. Missing data is just reality. Data may be incomplete, the values unknown. SQL is designed for that. It is designed to handle reality. Whereas null references are not, they cause problems you do not need... Data != reference you can avoid the issue of allowing invalid references everywhere you can not avoid incomplete data.