mysql 循环一个表数据

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

DELIMITER //

CREATE PROCEDURE IncrementAge()
BEGIN
    DECLARE done INT DEFAULT FALSE;
    DECLARE userId INT;
    DECLARE userAge INT;
    
    -- 声明游标
    DECLARE cur CURSOR FOR SELECT id, age FROM users;
    
    -- 声明结束标志
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;
    
    OPEN cur;
    
    read_loop: LOOP
        FETCH cur INTO userId, userAge;
        
        IF done THEN
            LEAVE read_loop;
        END IF;
        
        -- 更新年龄
        UPDATE users SET age = age + 1 WHERE id = userId;
    END LOOP;
    
    CLOSE cur;
END //

DELIMITER ;

CALL IncrementAge();