MySQL CHAR() function will ignore NULL if it is provided as an argument to it. To understand it, consider the following examples −
mysql> Select CHAR(65,66,67,NULL); +---------------------+ | CHAR(65,66,67,NULL) | +---------------------+ | ABC | +---------------------+ 1 row in set (0.00 sec) mysql> Select CHAR(NULL,66,67,NULL); +-----------------------+ | CHAR(NULL,66,67,NULL) | +-----------------------+ | BC | +-----------------------+ 1 row in set (0.00 sec)
In both the examples above, CHAR() function ignores the NULL and converts the numeric value into character value.