Index column size too large

ERROR 1709 (HY000) at line 50558: Index column size too large. The maximum column size is 767 bytes.

解决办法:
步骤1:
set global innodb_file_format = BARRACUDA;
set global innodb_large_prefix = ON;

步骤2:修改创建表的脚本，条件如下项目
ROW_FORMAT=DYNAMIC
DROP TABLE IF EXISTS `monxin_weixin_authcode`;
CREATE TABLE `monxin_weixin_authcode` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `openid` varchar(32) DEFAULT NULL COMMENT '用户openid',
  `code` varchar(32) DEFAULT NULL COMMENT '验证码',
  `time` bigint(12) NOT NULL DEFAULT '0' COMMENT '时间',
  `wid` varchar(32) DEFAULT NULL COMMENT '微信号原始ID',
  PRIMARY KEY (`id`)
)  DEFAULT CHARSET=utf8mb4 ROW_FORMAT=DYNAMIC COMMENT='梦行微信 微信验证码';