trying to break down results of SQL query to show data for each month - sql-server

Question

I'm very new to SQL and have a problem I can't figure out.
I'm trying to replace an excel spreadsheet and turn it into a PowerBi report. Currently our team runs the following query to get the amount of active users every month and types it into an excel sheet which then graphs the number of users each month showing the increase. Since I don't want to manually input data each month my goal is to break down this query to give the current number of users in each month and add to that every month.
Desired result would look something like this
dateCreated # of Users
----------------------
2008-10 295
2008-11 355
2008-12 470
2009-01 522
I was able to break it down enough to give me the amount created each month, but that doesn't give me the total amount each month. This is the query that I used and a sample of the results I got.
SELECT
FORMAT(USERADDR.DateCreated, 'yyyy-MM') AS 'dateCreated',
COUNT(s.UserId) AS "# of Users"
FROM
ER.dbo.ssUser s,
ER.dbo.ssUserAddress USERADDR,
ER.dbo.ssAddress ADDRESS
WHERE
s.UserId = USERADDR.UserId
AND USERADDR.AddressId = ADDRESS.AddressId
AND Isdefault = 1
AND Type = 'soldto'
GROUP BY
FORMAT(USERADDR.DateCreated, 'yyyy-MM')
result sample:
dateCreated # of Users
2008-10 295
2008-11 41
2008-12 22
2009-01 19
This is almost there, but I need a running total. I've tried a lot of different things including SUM, SUM OVER, COUNT OVER etc. My boss suggested a while loop. I can't get that to work either and everything I've read says that should be the last resort. Here is one example of my failed attempts
SELECT
FORMAT(USERADDR.DateCreated, 'yyyy-MM') as 'dateCreated',
COUNT(s.UserId)
OVER(
PARTITION BY Month(USERADDR.DateCreated)
GROUP BY FORMAT(USERADDR.DateCreated, 'yyyy-MM')
)
AS "# of Users"
FROM
ER.dbo.User s,
ER.dbo.UserAddress USERADDR,
ER.dbo.Address ADDRESS
WHERE
s.UserId = USERADDR.UserId
AND USERADDR.AddressId = ADDRESS.AddressId
AND Isdefault = 1
AND Type = 'soldto'
--original query which gives total number of users right now.
SELECT
count(s.UserId) AS "# of Users"
FROM
ER.dbo.User s,
ER.dbo.UserAddress USERADDR,
ER.dbo.Address ADDRESS
WHERE
s.UserId = USERADDR.UserId
AND USERADDR.AddressId = ADDRESS.AddressId
AND Isdefault = 1
AND Type = 'soldto'

Answer 1

You can do a window sum() on the aggregated count of users per month, like so:
SELECT
FORMAT(USERADDR.DateCreated, 'yyyy-MM') [dateCreated],
SUM(COUNT(s.UserId)) OVER(ORDER BY FORMAT(USERADDR.DateCreated, 'yyyy-MM')) [# of Users]
FROM
ER.dbo.ssUser s
INNER JOIN ER.dbo.ssUserAddress USERADDR
ON s.UserId = USERADDR.UserId,
INNER JOIN ER.dbo.ssAddress ADDRESS
ON USERADDR.AddressId = ADDRESS.AddressId
WHERE Isdefault = 1 AND Type = 'soldto'
group by FORMAT(USERADDR.DateCreated, 'yyyy-MM')
Notes:
always prefer proper, explicit join syntax (with the ON keyword) over implicit, old-school joins, who were deprecated long time ago - I modified your query accordingly
SQLServer uses square brackets for identifiers - you should avoid single quotes, as they are generally used for litteral strings
you have unqualified column names in the WHERE clause: always qualify column names in your query, so it is easy to understand to which table they belong