本文介绍了按月分组并在未找到数据时返回 0的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

我已经尝试修复我的查询好几天了:(.它应该按月分组,如果没有找到记录,则返回 0.一个例子:

I have been trying to fix my query for days now :(.It is supposed to group by month and return 0 if record is not found.An example:

    SELECT MONTH(created_at) AS month_num,
DATE_FORMAT(created_at, '%b') AS month_name, COUNT(*) AS total_num
    FROM table WHERE user_id=1384249399168
    GROUP BY MONTH(created_at) ORDER BY created_at DESC

结果:

month_num       month_name       total_num
     8            Aug                 20
     7            Jul                 15
     5            May                 39
     2            Feb                 10
     1            Jan                 8

预期结果:

month_num       month_name       total_num
         12           Dec                 0
         11           Nov                 0
         10           Oct                 0
         9            Sep                 0
         8            Aug                 20
         7            Jul                 15
         6            Jun                 0
         5            May                 39
         4            Apr                 0
         3            Mar                 0
         2            Feb                 10
         1            Jan                 8

我尝试了很多答案,尤其是这个 ​​MySql 计数() 如果没有找到记录,则返回 0 但没有成功.

I have tried a lot of answers especially this MySql count() to return 0 if no records found but without success.

请问有什么帮助吗?

推荐答案

这篇文章解决了我的问题.我必须创建一个包含所有 12 个月的表格.

This post solved my problem.I had to create a table which contains all the 12 months.

mysql选择每个月的记录数感谢任何人,尤其是@Turdaliev

mysql select the count of records for every monthThanks anyone especially @Turdaliev

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