通过游标高效的完成商品点击量的统计
1:首先需要mysql的事件支持
SHOW VARIABLES LIKE 'event_scheduler';为off,则执行SET GLOBAL event_scheduler = ON;
2:建立一个商品表和一个商品点击记录表
CREATE TABLE `commodity` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`price` decimal(8,2) NOT NULL DEFAULT '0.00',
`title` varchar(20) NOT NULL DEFAULT '',
`all_click` int(11) NOT NULL DEFAULT '0',
`date` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00' ON UPDATE CURRENT_TIMESTAMP,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
CREATE TABLE `commodity_log` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`commodity_id` int(11) NOT NULL DEFAULT '0',
`user_id` int(11) NOT NULL DEFAULT '0',
`num` int(11) NOT NULL DEFAULT '1',
`date` date NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
3:通过一个存储过程来模拟商品记录的插入
input_commodity_log(IN _commodity_id INT,IN _user_id INT)#注:_commodity_id 为商品id,_user_id为用户id
BEGIN
set @num=0;
set @log_num=0;
select * from commodity where id=_commodity_id limit 1;
set @num=FOUND_ROWS();
if @num=1 THEN
SELECT count(*) INTO @log_num from commodity_log WHERE commodity_id=_commodity_id and user_id=_user_id and date=CURRENT_DATE();
if @log_num>0 THEN
UPDATE commodity_log SET num=num+1 WHERE commodity_id=_commodity_id and user_id=_user_id and date=CURRENT_DATE();
ELSE
INSERT INTO commodity_log (commodity_id,user_id,date) VALUES (_commodity_id,_user_id,CURRENT_DATE());
END IF;
END IF;
END
执行:CALL input_commodity_log(商品id,用户id)
4:再通过一个存储过程来完成点击记录插入到商品表
count_commodity()
BEGIN
DECLARE c_id INT; #定义商品id
DECLARE cnum INT;
#定义商品点击量
DECLARE isend INT DEFAULT 0; #游标状态
DECLARE cur CURSOR FOR SELECT commodity_id,SUM(num) FROM commodity_log WHERE DATE=DATE_SUB(CURDATE(),INTERVAL 1 DAY) GROUP BY commodity_id; #将结果集放进游标,并且统计前一天的数据
DECLARE CONTINUE HANDLER FOR NOT FOUND SET isend=1; #当游标结束的时候,isend为1
OPEN cur; #开启游标
FETCH cur INTO c_id,cnum; #将游标的数据赋予预先定义好的参数
WHILE isend!=1 do
UPDATE commodity SET all_click=cnum+all_click where id=c_id;
FETCH cur INTO c_id,cnum;
END WHILE;
CLOSE cur; #关闭游标
END
5:通过mysql的事件,完成每天5点统计点击量
DELIMITER $$
ALTER DEFINER=`root`@`127.0.0.1` EVENT `update_clicknum` ON SCHEDULE EVERY 1 DAY STARTS '2017-03-22 05:00:00' ON COMPLETION NOT PRESERVE ENABLE DO CALL count_commodity$$
DELIMITER ;
#备注:该方法主要用于数据量大的系统,并且统计的是前一天的商品访问数据