Syntax:
IS_IPV6(expr)

Returns 1 if the argument is a valid IPv6 address specified as a
string, 0 otherwise, unless expr is NULL, in which case the function
returns NULL. This function does not consider IPv4 addresses to be
valid IPv6 addresses.

URL: https://dev.mysql.com/doc/refman/8.0/en/miscellaneous-functions.html

