MySql-一组时间戳数据（时间戳，事件），每天计算事件

Question

I have a table: id, datetime, event

i also have table dates: date (Ymd format)

the problem is some days don't have any events, I would like them to show 0 (or null)

SELECT DATE_FORMAT(table.timestamp, '%Y-%m-%d') ydm, count(table.fkUID) FROM `table`  where table.fkUID=$var group by ydm;

is there some way to join or use conditional statements to make the result show:

date|count
----------
2010-05-23| 5
2010-05-24| 0  <--- this line just doesn't exist in my query.
2010-05-26| 3

Answer 1

select d.date,count(e.timestamp)
from dates d
left join events e on d.date=DATE_FORMAT(e.timestamp,'%Y-%m-%d')
group by d.date;

I don't have environment for testing, and I'm not sure that I am clear about the question, but here it is my guess.

Answer 2

The accepted wisdom seems to be that you have to create a table containing a list of all the dates you're interested in and then do an outer join on with the view you have there. Sucks, I know.