Question

我正在尝试在MySQL中按月对销售数据进行分组，但是具有滚动的年度总和值。预期输出示例：

Month                           SUM
January 2018    Total from february 2017 to january 2018 (12months)
February 2018   Total from march 2017 to february 2018 (12months)
...

这是我到目前为止得到的：

SELECT YEAR(date), MONTH(date), 
(SELECT SUM(quantity) FROM tb t2 WHERE t2.date BETWEEN DATE_SUB(t1.date, INTERVAL 1 YEAR) AND t1.date)
FROM tb t1
WHERE date BETWEEN '2018-01-01' AND '2019-01-01'
GROUP BY YEAR(date), MONTH(date)

结果是预期的，但是效率很低，因为如果我使用3天的间隔，则需要30秒才能运行（所以我什至不能以1年的间隔运行）

任何想法如何改进此查询，以便我可以使用1年间隔？在特定字段上是否需要索引？

修改：创建语句：

CREATE TABLE IF NOT EXISTS `tb` (
  `inc` int(11) NOT NULL AUTO_INCREMENT,
  `quantity` float NOT NULL,
  `date` datetime NOT NULL,
  PRIMARY KEY (`inc`),
  KEY `date` (`date`)
) ENGINE=InnoDB;

它有超过10万行，我无法升级到MySQL> = 8

Answer 1

代替使用子查询，“内部自连接”可以更有效。请尝试以下操作：

SELECT 
  YEAR(t1.date), 
  MONTH(t1.date), 
  SUM(t2.quantity) 
FROM tb AS t1 
JOIN tb AS t2 
  ON t2.date BETWEEN (t1.date - INTERVAL 1 YEAR) AND t1.date 
WHERE t1.date BETWEEN '2018-01-01' AND '2019-01-01'
GROUP BY YEAR(t1.date), MONTH(t1.date)

按月分组，汇总值和滚动年份

1 个答案: