来自https://dev.mysql.com/doc/refman/5.0/en/mathematical-functions.html#function_rand
...RAND(N)...If a constant integer argument N is specified, it is used as the seed value,...
N的最大可能值是什么?
说"整数"它们是指 mysql 类型整数(已签名为-2147483648,2147483647 / unsigned 0,4294967295)或其他什么内容?