In a Zen-like manner, "NULL" is never equal to anything, even itself. Therefore comparisons using equality operators will always return ``False``, even when the value actually ``IS NULL``.
For that reason, comparison operators should never be used to make comparisons with ``NULL``; ``IS NULL`` and ``IS NOT NULL`` should be used instead.
== Noncompliant Code Example
----
UPDATE books
SET title = 'unknown'
WHERE title = NULL -- Noncompliant
== Compliant Solution
WHERE title IS NULL
