创建存储过程，对于读者编号，逐条检查借阅表中该读者的借阅情况：换水日期为空记录，借阅天数=系统日期-借阅日期，如借阅日期天数小于15天，则输出“正常”；借阅天数大于等于15天并且小于等于30天，则输出“通知还书”；借阅天数大于30天，则输出“逾期”。调用该存储过程，测试读者编号为“0001”的借阅情况

好的，根据您的要求，我已经创建了一个名为 `check_borrow_status` 的存储过程，如下所示：

CREATE PROCEDURE check_borrow_status(IN reader_id VARCHAR(10))
BEGIN
    DECLARE borrow_date DATE;
    DECLARE return_date DATE;
    DECLARE diff INT;
    DECLARE status VARCHAR(20);
    
    SELECT MAX(borrow_date) INTO borrow_date
    FROM borrow_table
    WHERE reader_id = reader_id AND return_date IS NULL;
    
    IF borrow_date IS NULL THEN
        SELECT CONCAT('Reader ', reader_id, ' has no borrowed books') AS 'status';
    ELSE
        SET diff = DATEDIFF(CURRENT_DATE(), borrow_date);
        
        IF diff < 15 THEN
            SET status = 'Normal';
        ELSEIF diff >= 15 AND diff <= 30 THEN
            SET status = 'Notify to return book';
        ELSE
            SET status = 'Overdue';
        END IF;
        
        SELECT CONCAT('Reader ', reader_id, ' is ', status, ', borrow date is ', borrow_date) AS 'status';
    END IF;
END;

您可以通过调用该存储过程并传入参数 reader_id = '0001' 来测试该读者的借阅情况，如下所示：

CALL check_borrow_status('0001');

注意：您需要将 `borrow_table` 替换为您实际使用的借阅表名称。