Sum of Counts from successive dates - mysql

Question

I need to get the total number of an item for every month.
So far, with the following code :
Select Count(mpay_collector_company.id) As `Number of Collector Companies`,
Month(mpay_collector_company.created_at) As Month,
Year(mpay_collector_company.created_at) As Year
From mpay_collector_company
Group By Month(mpay_collector_company.created_at),
Year(mpay_collector_company.created_at)
I have the following response :
#|Year|Month
------------
5|2014|11
3|2014|12
3|2015|1
7|2015|2
6|2015|3
2|2015|4
5|2015|6
1|2015|7
And instead of the number for each month I'd like to have the sum from the beginning for each month, which would be something like this :
Sum|Year|Month
--------------
5|2014|11
8|2014|12
11|2015|1
18|2015|2
24|2015|3
26|2015|4
31|2015|6
32|2015|7
Any ideas ?
EDIT : This request will be implemented as a view, so sub-requests are pretty much a no-go :x

Answer 1

Something like this could work:
Select Count(distinct previous_mpay_collector_company.id)+ Count(distinct mpay_collector_company.id) As `Number of Collector Companies`,
Month(mpay_collector_company.created_at) As Month,
Year(mpay_collector_company.created_at) As Year
From mpay_collector_company
Left Join mpay_collector_company previous_mpay_collector_company
On Year(mpay_collector_company.created_at) > Year(previous_mpay_collector_company.created_at)
OR (Month(mpay_collector_company.created_at) > Month(previous_mpay_collector_company.created_at)
And Year(mpay_collector_company.created_at) >= Year(previous_mpay_collector_company.created_at))
And previous_mpay_collector_company.id <> mpay_collector_company.id
Group By Month(mpay_collector_company.created_at),
Year(mpay_collector_company.created_at);
The trick would be self joining to all of the previous months and counting from the joined table.

Answer 2

You can first select distinct year.months and then check count for each value
select year,month ,
( SELECT count(*) FROM mpay_collector_company WHERE
Year(mpay_collector_company.created_at) <= temp1.year
AND
Month(mpay_collector_company.created_at) <= temp1.month
)
from (
Select DISTINCT
Month(mpay_collector_company.created_at) As month,
Year(mpay_collector_company.created_at) As year
From mpay_collector_company
) as temp1
ORDER BY year,month
if you want to "reset" for each year , just change comparison to EQUAL between years and thats it
select year,month ,
( SELECT count(*) FROM mpay_collector_company WHERE
Year(mpay_collector_company.created_at) = temp1.year
AND
Month(mpay_collector_company.created_at) <= temp1.month
)
from (
Select DISTINCT
Month(mpay_collector_company.created_at) As month,
Year(mpay_collector_company.created_at) As year
From mpay_collector_company
) as temp1
ORDER BY year,month

Answer 3

Using a correlated subquery to count the number of rows with a date before the current should work too:
Select
Count(id) As "Number of Collector Companies",
Month(created_at) As Month,
Year(created_at) As Year,
(
Select Count(*)
From mpay_collector_company
Where EXTRACT(YEAR_MONTH from created_at) <= EXTRACT(YEAR_MONTH from m.created_at)
) as running_count
From mpay_collector_company m
Group By Year(created_at), Month(created_at);
Sample SQL Fiddle showing it in action

Answer 4

Select
(Select Sum(Count(Z.id)) FROM mpay_collector_company z
where z.created_at <= A.created_at) as '#',
Month(A.created_at) As Month,
Year(A.created_at) As Year
From mpay_collector_company A
Group By Month(mpay_collector_company.created_at),
Year(mpay_collector_company.created_at)
This should do it for ya,