php - 如何计算 SQL 中每个值的表行数？

Question

我是新来的，所以如果它没有固定的主题，请修复我。我有这张表:

id | uid | month | year
-----------------------
1 | 5 | 12 | 2018
2 | 5 | 12 | 2018
3 | 9 | 12 | 2018
4 | 3 | 01 | 2019

我想计算每个uid有多少次month和year值等于 - month=12和 year=2018

例如我想得到这样的响应:

uid=5 - count = 2
uid=9 - count = 1

这怎么可能？

Answer 1

使用按 uid 分组:

select uid, count(*) as counter
from table
where month = 12 and year = 2018
group by uid