Question

我头疼解决以下问题。

我们正在寻找一个查询，当SUM（price_total）达到按类型分组的特定级别时，它会检索数据。表结构如下：

CREATE TABLE `Table1` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `Date` datetime DEFAULT NULL,
  `type` int(11) DEFAULT NULL,
  `price_total` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=8 DEFAULT CHARSET=latin1;

数据

INSERT INTO `Table1` (`id`, `Date`, `type`, `price_total`)
VALUES
    (1,'2013-02-01 00:00:00',1,5),
    (2,'2013-02-01 00:00:00',2,15),
    (3,'2013-02-02 00:00:00',1,25),
    (4,'2013-02-03 00:00:00',3,5),
    (5,'2013-02-04 00:00:00',4,15),
    (6,'2013-03-05 00:00:00',1,20),
    (7,'2013-08-07 00:00:00',4,15);

阈值15的示例结果，按时间顺序排列。

Type 1: 2013-02-02 00:00:00 Because here it came above 15. (15+5)
Type 2: 2013-02-01 00:00:00
Type 3: n/a SUM(price_total) < 15
Type 4: 2013-02-04 00:00:00

总结一下。我想知道他们越过门槛的日期。价格总和应按时间顺序总结。

Answer 1

这是一个简单，自我解释的问题：

select type, min(date) as date
from (
    select t1.type, t1.date, sum(t2.price_total) as total
    from table1 t1
    join table1 t2
      on  t2.type  = t1.type
      and t2.date <= t1.date
    group by t1.type, t1.date
    having total >= 15
) sub
group by type

演示：http://rextester.com/GMAK8269

当达到某个限制时，MySQL会获得行

1 个答案: