要捕捉运行总量并保持先进先出属性的SQL,可以使用队列和触发器来实现。下面是一个示例解决方法:
CREATE TABLE running_total (
id INT AUTO_INCREMENT PRIMARY KEY,
value INT,
time TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);
CREATE TABLE running_queue (
id INT AUTO_INCREMENT PRIMARY KEY,
value INT,
type INT,
time TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);
DELIMITER $$
CREATE TRIGGER update_running_total
AFTER INSERT ON running_queue
FOR EACH ROW
BEGIN
IF NEW.type = 1 THEN
UPDATE running_total SET value = value + NEW.value;
ELSE
UPDATE running_total SET value = value - NEW.value;
END IF;
END$$
DELIMITER ;
-- 增加运行值
INSERT INTO running_queue (value, type) VALUES (10, 1);
-- 减少运行值
INSERT INTO running_queue (value, type) VALUES (5, -1);
SELECT value FROM running_total ORDER BY time ASC;
这样就可以捕捉运行总量并保持先进先出属性的SQL了。每次更新运行总量时,都会自动计算更新后的运行总量,并将更新记录保存在队列中,便于查询和回溯。