MySQL 1418错误解决方法
某一日，发现DB复制有问题

Last_Errno: 1418
                 Last_Error: Error 'This function has none of DETERMINISTIC, NO SQL, or READS SQL DATA in its declaration and binary logging is enabled (you *might* want to use the less safe log_bin_trust_function_creators variable)' on query. Default database: 'elearning_project_sxgzjs'. Query: 'CREATE DEFINER=`root`@`localhost` FUNCTION rand_string(n INT)
RETURNS VARCHAR(255)
BEGIN
    DECLARE chars_str varchar(100) DEFAULT '23456789abcdefghijkmnpqrstuvwxy';
    DECLARE return_str varchar(255) DEFAULT '';
    DECLARE i INT DEFAULT 0;
    WHILE i < n DO
        SET return_str = concat(return_str,substring(chars_str , FLOOR(RAND()*31 ),1));
        SET i = i +1;
    END WHILE;
    RETURN return_str;
END'



可以用命令行方式登录MYSQL执行下面的语句解决问题：

mysql> SET GLOBAL log_bin_trust_function_creators = 1;