Using the 'IS (NOT) DISTINCT FROM' SQL Comparators

In a recent SQL statement, I stumbled upon an issue regarding the handling of NULL values within a given predicate. Coming from languages such as PHP, which are very liberal in their type coercion (NULL can be treated as a falsy value), I was surprised to find how the inclusion of such a value resulted in a sort of predicate short-circuiting. This occurs because NULL, in its strictest sense, is an unknown value. As such, the entire condition is deemed unknown in the event of its presence. However, if you wish to weaken this constraint within a comparison, you can take advantage of IS DISTINCT FROM, which instead treats NULL as a known value. This difference can be best highlighted in a small logic table, where we first describe how the presence of a NULL value takes over the entire predicate result.

NULL != NULL = NULL
NULL != TRUE = NULL
TRUE != NULL = NULL

Using the IS DISTINCT FROM comparator instead, we can treat NULL as a known value, which then returns the desired Boolean result.

NULL IS DISTINCT FROM NULL = FALSE
NULL IS DISTINCT FROM TRUE = TRUE
TRUE IS DISTINCT FROM NULL = TRUE