Is there a reason not to use <=> (null safe equals operator) in mysql instead of =?

Question

MySQL provides a nice operator <=> that works with comparisons that could contain a null such as null <=> null or null <=> 5

Answer 1

The big difference between null in mySQL and in programming languages is that in mySQL, null means unknown value while in programming it means undefined value.

In mySQL, null does not equal null (unknown does not equal unknown). While in programming languages, null does equal null (undefined equals undefined).