如何每年重置表中的MySQL列？

DELIMITER //

CREATE PROCEDURE reset_table_columns()
BEGIN
    DECLARE column_name VARCHAR(255);
    DECLARE done INT DEFAULT FALSE;
    DECLARE cur CURSOR FOR SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 'your_table_name';
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;

    OPEN cur;

    read_loop: LOOP
        FETCH cur INTO column_name;
        IF done THEN
            LEAVE read_loop;
        END IF;

        SET @sql = CONCAT('ALTER TABLE your_table_name MODIFY COLUMN ', column_name, ' DEFAULT NULL');
        PREPARE stmt FROM @sql;
        EXECUTE stmt;
        DEALLOCATE PREPARE stmt;
    END LOOP;

    CLOSE cur;
END //

DELIMITER ;

CALL reset_table_columns();