1. Quote of the Week
If SQL is based on relational algebra which is based on set theory where the concept of null set (empty set) is an axiom of the theory. In this theory empty set is not the same thing as nothing. A point that confuses many people.
Relational algebra is based on 3VL predicates, that is, the answer to any predicate can have three states true, false or unknown. Unknown is caused by the use of a operator on an the absence of a value (null). Within relational algebra null is not to be treated as a value but merely a marker of unknown (absence of a value).
None of this is rocket science and I suggest doesn't result in bad implications. I suggest the so called "bad implications" are only introduced as people use null as a patch for problems for example the division by zero. indeterminate state, open ended ranges, data states to name a few. That is, the issue is not the concept of null but its abuse as a patch for other issues.
2. To Laugh or Cry?
3. Online debunking
5. And now for something completely different
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