mysql主键id的生成方式（自增、唯一不规则）

1、利用uuid函数生成唯一且不规则的主键id

sql：

CREATE TABLE `test` (
  `id` varchar(100) COLLATE utf8_estonian_ci NOT NULL COMMENT '唯一不重复',
  `create_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `update_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  `sex` int(11) DEFAULT NULL,
  `name` varchar(255) COLLATE utf8_estonian_ci DEFAULT NULL,
  `username` varchar(255) COLLATE utf8_estonian_ci DEFAULT NULL,
  `password` varchar(255) COLLATE utf8_estonian_ci DEFAULT NULL,
  `classes` varchar(255) COLLATE utf8_estonian_ci DEFAULT NULL,
  `major` int(255) DEFAULT NULL,
  `QQ` int(20) DEFAULT NULL,
  `introducemyself` varchar(255) COLLATE utf8_estonian_ci DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_estonian_ci ROW_FORMAT=DYNAMIC;

表:

插入语句：

INSERT INTO test(id,sex,name,username,password,classes,major,QQ,introducemyself) VALUE(replace(uuid(), '-', ''),1,"小米","xck","001","八班",265,953190259,"我最牛");

执行了俩次，生成了俩个不同id：

2、id实现自动增长

将类型改为整型，下方选择自动增长

 看DDL：

CREATE TABLE `test` (
  `id` bigint(100) NOT NULL AUTO_INCREMENT COMMENT '唯一不重复',
  `create_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `update_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  `sex` int(11) DEFAULT NULL,
  `name` varchar(255) COLLATE utf8_estonian_ci DEFAULT NULL,
  `username` varchar(255) COLLATE utf8_estonian_ci DEFAULT NULL,
  `password` varchar(255) COLLATE utf8_estonian_ci DEFAULT NULL,
  `classes` varchar(255) COLLATE utf8_estonian_ci DEFAULT NULL,
  `major` int(255) DEFAULT NULL,
  `QQ` int(20) DEFAULT NULL,
  `introducemyself` varchar(255) COLLATE utf8_estonian_ci DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_estonian_ci ROW_FORMAT=DYNAMIC;

插入一条数据，sql：

INSERT INTO test(sex,name,username,password,classes,major,QQ,introducemyself) VALUE(1,"小米","xck","001","八班",265,953190259,"我最牛");

对应数据库变化：