将SQL组数据放入Year + Week Number箱中

Question

I have a list of businesses and their creation date, and I want to group them into bins of year + week number - but the catch is that if there were no businesses created in week 1 in 2015 i still want it to show this bin with '0'.

The following query skips weeks that there were no businesses created:

SELECT Date_Format(created,'%X %V') as d, count(*) as Biz
FROM businesses b
GROUP BY d
ORDER BY d asc

Anyone know How I can add the missing bins and keep it dynamic? meaning that when I run it in 2 weeks I'll get 2 new bins even if there were no businesses created in those 2 weeks. Thanks!

Answer 1

Try the attached query

select 
Date_Format(M1,'%X %V'),count(b.*)
from
(
select 
'2015-01-01'  +INTERVAL m WEEK as m1
from
(
select @rownum:=@rownum+1 as m from
(select 1 union select 2 union select 3 union select 4) t1,
(select 1 union select 2 union select 3 union select 4) t2,
(select 1 union select 2 union select 3 union select 4) t3,
(select @rownum:=-1) t0
) d1
) d2
LEFT JOIN businesses b on Date_Format(b.created,'%X %V')=Date_Format(M1,'%X %V')
group by
Date_Format(M1,'%X %V')
order by m1