mysql插入id

-- 创建表时设置id为自增
CREATE TABLE table_name (
    id INT AUTO_INCREMENT PRIMARY KEY,
    column1 datatype,
    column2 datatype,
    ...
);

-- 插入数据时不指定id
INSERT INTO table_name (column1, column2, column3, ...)
VALUES (value1, value2, value3, ...);

-- 检查id是否存在
SELECT COUNT(*) FROM table_name WHERE id = desired_id;

-- 如果id不存在，则插入数据
INSERT INTO table_name (column1, column2, column3, ...)
SELECT value1, value2, value3, ...
WHERE NOT EXISTS (SELECT 1 FROM table_name WHERE id = desired_id);

-- 创建表
CREATE TABLE users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    username VARCHAR(50) NOT NULL,
    email VARCHAR(100) NOT NULL
);

-- 插入数据
INSERT INTO users (username, email)
VALUES ('john_doe', 'john@example.com');

-- 查询数据
SELECT * FROM users;