mysql如何设置标识列

CREATE TABLE table_name (
    column_name datatype AUTO_INCREMENT,
    ...
    PRIMARY KEY (column_name)
);

CREATE TABLE students (
    id INT AUTO_INCREMENT,
    name VARCHAR(100),
    age INT,
    PRIMARY KEY (id)
);

ALTER TABLE table_name ADD COLUMN column_name datatype AUTO_INCREMENT;

ALTER TABLE students ADD COLUMN id INT AUTO_INCREMENT PRIMARY KEY;

ALTER TABLE table_name AUTO_INCREMENT = 1;

ALTER TABLE students AUTO_INCREMENT = 1;

ALTER TABLE table_name MODIFY COLUMN column_name new_datatype AUTO_INCREMENT;

ALTER TABLE students MODIFY COLUMN id BIGINT AUTO_INCREMENT;