mysql实现sequence

CREATE TABLE sequence_table (
    id INT AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(255)
);

INSERT INTO sequence_table (name) VALUES ('Alice');
INSERT INTO sequence_table (name) VALUES ('Bob');

SELECT id FROM sequence_table;

CREATE TABLE sequence_table (
    id INT PRIMARY KEY,
    name VARCHAR(255)
);

DELIMITER $$
CREATE TRIGGER before_insert_sequence
BEFORE INSERT ON sequence_table
FOR EACH ROW
BEGIN
    SET NEW.id = (SELECT IFNULL(MAX(id), 0) + 1 FROM sequence_table);
END $$
DELIMITER ;

INSERT INTO sequence_table (name) VALUES ('Alice');
INSERT INTO sequence_table (name) VALUES ('Bob');

SELECT id FROM sequence_table;

CREATE TABLE sequence_table (
    id INT PRIMARY KEY,
    name VARCHAR(255)
);

DELIMITER $$
CREATE PROCEDURE generate_sequence(IN p_name VARCHAR(255), OUT p_id INT)
BEGIN
    SELECT IFNULL(MAX(id), 0) + 1 INTO p_id FROM sequence_table;
    INSERT INTO sequence_table (id, name) VALUES (p_id, p_name);
END $$
DELIMITER ;

CALL generate_sequence('Alice', @id);
CALL generate_sequence('Bob', @id);

SELECT id FROM sequence_table;