SQL查询每天汇总数据

Question

I use following SQL query to get data from MySQL database.

select
    classid,start,
    count(case when classid='Handball' then 1 end) as handball_count
from signature where classid='Handball'
group by start

Date is for example 2016.12.01. 10:51:58 format.

It should be on a daily basis, so for example 2016.12.01. 10:51:58 and 2016.12.01. 15:51:58 shouldn't be a different entry in this query. How should I group by day? I would like to summarize participants for each activity per day and not separated by the date of the participant's signature.

Answer 1

you can try this

SELECT count(case when classid='Handball' then 1 end) as handball_count,
   classid,DATE(start) DateOnly 
FROM signature where classid='Handball'
GROUP BY DateOnly;