mysql 字符串枚举类型转换

CREATE TABLE table_name (
    column_name ENUM('value1', 'value2', 'value3', ...)
);

SELECT column_name + 0 AS enum_value, column_name AS enum_string
FROM table_name;

INSERT INTO table_name (column_name) VALUES ('value1');

SHOW COLUMNS FROM table_name LIKE 'column_name';

ALTER TABLE table_name MODIFY column_name ENUM('value1', 'value2', 'value3', '') DEFAULT NULL;

CREATE TABLE users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(255),
    gender ENUM('male', 'female', 'unknown')
);

INSERT INTO users (name, gender) VALUES ('Alice', 'female');
INSERT INTO users (name, gender) VALUES ('Bob', 'male');
INSERT INTO users (name, gender) VALUES ('Charlie', 'unknown');

SELECT id, name, CASE gender WHEN 'male' THEN '男' WHEN 'female' THEN '女' WHEN 'unknown' THEN '未知' END AS gender_str
FROM users;