Question

嗨，我在按月份对图像数据进行排序时遇到了麻烦，我想通过获取计数和按月的分组来确定在某个月份内创建，更新和删除了多少张图像。我有两个包含图像数据的表。两个表都有'createdAt'，'updatedAt'和'deletedAt'列，所以我所做的是将两个表的列设置为日期格式，并将它们合并为所有数据，但是我无法获取数据计数。这是我到目前为止的内容：

SELECT DATE_FORMAT(`createdAt`, "%M %Y"), DATE_FORMAT(`updatedAt`, "%M %Y"), DATE_FORMAT(`deletedAt`, "%M %Y") FROM harvest_sample_images UNION SELECT DATE_FORMAT(`createdAt`, "%M %Y"), DATE_FORMAT(`updatedAt`, "%M %Y"), DATE_FORMAT(`deletedAt`, "%M %Y") FROM plant_sample_images

任何帮助将不胜感激。

SELECT DATE_FORMAT(`createdAt`, "%M %Y") DAT, count(*) AS `created`,
(SELECT DATE_FORMAT(`updatedAt`, "%M %Y") DAT, COUNT(*)) AS `updated`,
(SELECT DATE_FORMAT(`deletedAt`, "%M %Y") DAT COUNT(*)) AS `deleted`
FROM (SELECT `createdAt`, `updatedAt`, `deletedAt` FROM harvest_sample_images UNION SELECT `createdAt`, `updatedAt`, `deletedAt` FROM plant_sample_images)
GROUP BY DATE_FORMAT(`created`, "M% %Y")

我已经尝试过了。

所以我可能已经找到了另一种方法，将图像信息与计数分别显示在每个月中，并显示其所属月份。

SELECT DATE_FORMAT(`timestamp_date`, "%M %Y") AS `Month`,
(SELECT COUNT(*) FROM (SELECT `createdAt` FROM harvest_sample_images UNION ALL SELECT `createdAt` FROM plant_sample_images) AS `images_created` WHERE DATE_FORMAT(images_created.`createdAt`, "%m %y") = DATE_FORMAT(`timestamp_date`, "%m %y")) AS `Created`,
(SELECT COUNT(*) FROM (SELECT `updatedAt` FROM harvest_sample_images UNION ALL SELECT `updatedAt` FROM plant_sample_images) AS `images_updated` WHERE DATE_FORMAT(images_updated.`updatedAt`, "%m %y") = DATE_FORMAT(`timestamp_date`, "%m %y")) AS `Updated`,
(SELECT COUNT(*) FROM (SELECT `deletedAt` FROM harvest_sample_images UNION ALL SELECT `deletedAt` FROM plant_sample_images) As `images_deleted` WHERE DATE_FORMAT(images_deleted.`deletedAt`, "%m %y") = DATE_FORMAT(`timestamp_date`, "%m %y")) AS `Deleted`
FROM table_dates

所以我现在要做的是，创建了另一个表，该表的日期列表从数据的开始到现在。然后，我遍历数据并检查table_dates的格式化日期是否等于两个图像表date的并集的格式化日期。我得到计数并将其添加为新表中的列。思想得到赞赏

Answer 1

您需要计数和分组

select  year(createdAt) year , month(createdAt) month, count(*)
from  my_table  
group by   year(createdAt), month(createdAt)

或

SELECT DATE_FORMAT(`createdAt`, "%M %Y")  DAT, count(*)
from  my_table  
group by   DATE_FORMAT(`createdAt`, "%M %Y")

您可以使用join的3个计数

select t1.year_month, t1.count_create, t2.count_update, t3count_delete
from (
  SELECT DATE_FORMAT(`createdAt`, "%M %Y") year_month , count(*) count_create 
  from  my_table  
  group by   DATE_FORMAT(`createdAt`, "%M %Y")
) t1 
left join (
  SELECT DATE_FORMAT(`updatedAt`, "%M %Y") year_month , count(*) count_update 
  from  my_table  
  group by   DATE_FORMAT(`updatedAt`, "%M %Y")

) t2 ON t1.year_month = t2.year_month
left join (
  SELECT DATE_FORMAT(`deletedAt`, "%M %Y") year_month , count(*) count_delete 
  from  my_table  
  group by   DATE_FORMAT(`deletedAt`, "%M %Y")

) t3 ON t1.year_month = t3.year_month

在mySQL中统计某个月内的数据

1 个答案: