MySQL enum 枚举

性别 gender 男 女 保密

enum(数据值 1，数据值 2...);

-- Enum(0=>'男', 1=>'女', 2=>'保密')
create table my_enum(
    gender enum('男', '女', '保密')
)

mysql> desc my_enum;
+--------+----------------------------+------+-----+---------+-------+
| Field  | Type                       | Null | Key | Default | Extra |
+--------+----------------------------+------+-----+---------+-------+
| gender | enum('男','女','保密')     | YES  |     | NULL    |       |
+--------+----------------------------+------+-----+---------+-------+

-- 插入规范数据
insert into my_enum (gender) values ('男');
insert into my_enum (gender) values ('女');

mysql> select * from my_enum;
+--------+
| gender |
+--------+
| 男     |
| 女     |
+--------+

-- MySQL 会自动类型转换，+、-、\*、/ 会将数据转换成数值，普通字符串转换为数值 0
select gender + 0 from my_enum;

mysql> select gender + 0 from my_enum;
+------------+
| gender + 0 |
+------------+
|          1 |
|          2 |
+------------+

-- 可以直接插入数值数据
insert into my_enum (gender) values (1);

mysql> select * from my_enum;
+--------+
| gender |
+--------+
| 男     |
| 女     |
| 男     |
+--------+