= *(last-3)) { return(*(unsigned char *)(first-3) - *(unsigned char *)(last
= *(last-3)) { return(*(unsigned char *)(first-3) - *(unsigned char *)(last
last-N 形式的表达式可用于相对地址和范围定义,如下所示: mysql> SELECT JSON_EXTRACT('[1, 2, 3, 4, 5]', '$[last-3 to last-1]'); +--------------------------------------------------------+ | JSON_EXTRACT('[1, 2, 3, 4, 5]', '$[last