Which statement about NULL in MySQL is correct?
- A NULL equals NULL
- B NULL is the same as zero
- C Comparisons with NULL using = return NULL, so IS NULL must be used
- D NULL is the same as an empty string
Answer
Comparisons with NULL using = return NULL, so IS NULL must be used
NULL represents an unknown value, so any comparison with it is unknown rather than true or false. IS NULL and IS NOT NULL are the correct tests.





