mysql存储循环数据库

-- 示例代码：循环队列的简单实现
CREATE TABLE circular_queue (
    id INT AUTO_INCREMENT PRIMARY KEY,
    data VARCHAR(255),
    head INT DEFAULT 0,
    tail INT DEFAULT 0,
    size INT DEFAULT 10
);

DELIMITER $$
CREATE PROCEDURE enqueue(IN value VARCHAR(255))
BEGIN
    DECLARE current_tail INT;
    SET current_tail = (SELECT tail FROM circular_queue);
    UPDATE circular_queue SET data = value WHERE id = (current_tail % (SELECT size FROM circular_queue)) + 1;
    UPDATE circular_queue SET tail = (current_tail + 1) % (SELECT size FROM circular_queue);
END$$
DELIMITER ;

-- 示例代码：循环链表的简单实现
CREATE TABLE circular_linked_list (
    id INT AUTO_INCREMENT PRIMARY KEY,
    data VARCHAR(255),
    next_id INT,
    FOREIGN KEY (next_id) REFERENCES circular_linked_list(id)
);

-- 插入节点
INSERT INTO circular_linked_list (data, next_id) VALUES ('Node1', 2);
INSERT INTO circular_linked_list (data, next_id) VALUES ('Node2', 3);
INSERT INTO circular_linked_list (data, next_id) VALUES ('Node3', 1); -- 头节点指向尾节点

-- 示例代码：环形缓冲区的简单实现
CREATE TABLE ring_buffer (
    id INT AUTO_INCREMENT PRIMARY KEY,
    data VARCHAR(255),
    read_ptr INT DEFAULT 0,
    write_ptr INT DEFAULT 0,
    size INT DEFAULT 10
);

DELIMITER $$
CREATE PROCEDURE write_to_buffer(IN value VARCHAR(255))
BEGIN
    DECLARE current_write_ptr INT;
    SET current_write_ptr = (SELECT write_ptr FROM ring_buffer);
    UPDATE ring_buffer SET data = value WHERE id = (current_write_ptr % (SELECT size FROM ring_buffer)) + 1;
    UPDATE ring_buffer SET write_ptr = (current_write_ptr + 1) % (SELECT size FROM ring_buffer);
END$$
DELIMITER ;