Question

我有这个查询。

CREATE TABLE ip_logs (
  `ip_address` VARCHAR(11),
  `start_date` VARCHAR(11),
  `end_date` VARCHAR(11),
  `time_stamp`, VARCHAR(20),
  `mappings`, INTEGER,
  `loc_id` INTEGER
);

INSERT INTO ip_logs
  (`ip_address`,`start_date`,`end_date`,`time_stamp`,`mappings`, `loc_id`)
VALUES
 ('120.2.53.21','2020-01-03','2020-01-09','2020-01-03 14:33','2', '5'),
 ('198.3.222.2','2020-01-03','2020-01-14','2020-01-03 7:53', '7','4'),
 ('108.4.213.3','2020-01-04','2020-01-07','2020-01-04 12:13','3', '4'),
 ('128.5.173.4','2020-01-07','2020-02-15','2020-01-07 8:29', '12','3'),
 ('110.6.432.5','2020-01-07','2020-03-01','2020-01-07 11:45','4', '2'),
 ('198.7.222.6','2020-01-10','2020-01-14', '2020-01-10 17:32','8', '1'),
 ('118.8.113.7','2020-01-10','2020-01-19','2020-01-10 20:52','10', '4'),
 ('106.1.212.9','2020-02-24','2020-03-30','2020-02-24 10:08','5', '1');

我想生成“映射”列的7天平均值。例如，我要计算每天（从2020-01-03-2020-01-10开始）的平均映射。

结果：

 time_stamp | avg_mapping
 2020-01-03 | 4.5 (2 + 7) /2
 2020-01-04 | 3
 2020-01-07 | 8 (12 +4)/2
 2020-01-10 | 9

然后返回avg（avg_mapping）

Answer 1

我不明白您的问题与滚动平均值之间的关系。从数据和结果看，您似乎只想聚合并avg()：

select date(time_stamp) as time_stamp_day, avg(mapping) as avg_mapping
from ip_logs
group by date(time_stamp)

如果您想要结果集中第avg_mapping列的平均值（与mapping的总体平均值不同），则可以添加其他聚合级别：

select avg(avg_mapping) as avg_avg_mapping
from (
    select avg(mapping) as avg_mapping
    from ip_logs
    group by date(time_stamp)
) l

计算7天平均值

1 个答案: