Count last 10 data for each minute - sql

Question

I'm trying to write a SQL Query that has to return how many transactions were made in the last 10 minutes for each minute. Like:
1 minute ago : 2 transactions
2 minutes ago : 1 transaction
...
9 minutes ago : 3 transactions
10 minutes ago : 4 transactions
I was trying to do this query:
DECLARE #N int = 10;
DECLARE #NOW DATETIME = GETDATE();
WITH numbers( num ) AS (
SELECT 1 UNION ALL
SELECT 1 + num FROM numbers WHERE num < #N )
SELECT num AS minute,
(
SELECT COUNT(*) AS RESULTS
FROM [ApiTransactions]
WHERE [DateUtc] > DATEADD(year, -1, #NOW)
GROUP BY DATEPART(minute, DATEADD(minute, -num, #NOW))
)
FROM numbers;
I still don't know if the logic is right. What I know is that I'm receiving the error:
Each GROUP BY expression must contain at least one column that is not an outer reference.
Why I'm having this error? Is there a better way to do the query?

Answer 1

You don't need a numbers table for this, unless you need to fill in times with no transactions. I would start with this:
SELECT DATEADD(minute, DATEDIFF(minute, 0, DateUtc), 0) as the_minute, COUNT(*)
FROM ApiTransactions
WHERE DateUtc > DATEADD(minute, -10, DateUtc)
GROUP BY DATEADD(minute, DATEDIFF(minute, 0, DateUtc), 0)
ORDER BY the_minute;

Answer 2

You can use this one:
SELECT DATEDIFF(minute,[DateUtc],GETDATE()) as minutes_ago,
COUNT(*) tran_count
FROM ApiTransactions
WHERE DATEDIFF(second,[DateUtc],GETDATE()) <= 600 -- 10 minutes ago
GROUP BY DATEDIFF(minute,[DateUtc],GETDATE())
Output:
minutes_ago tran_count
0 2
1 3
2 10
3 15
4 4
5 9
6 12
7 6
8 13
9 4
10 2

Answer 3

I managed to solve my problem in two different ways:
DECLARE #N int = 10;
DECLARE #NOW DATETIME = GETDATE();
WITH numbers( num ) AS (
SELECT 1 UNION ALL
SELECT 1 + num FROM numbers WHERE num < #N )
SELECT num-1 AS minute,
(
SELECT COUNT(*) AS RESULTS
FROM [ApiTransactions]
WHERE [DateUtc] > DATEADD(minute, -num, #NOW) AND [DateUtc] < DATEADD(minute, -num+1, #NOW)
)
FROM numbers;
that has as output:
minutes_ago amount
0 4 (most recents. still being updated)
1 0
2 2
3 3
4 1
5 2
6 1
7 2
8 1
9 3
and with:
DECLARE #NOW DATETIME = GETDATE();
SELECT CONVERT(int, DATEDIFF(second, [DateUtc], #NOW)/60) as TimePassed, COUNT([TypeCode]) as Amount
FROM [ApiTransactions]
WHERE [DateUtc] >= DATEADD (minute, -10 , #NOW)
GROUP BY CONVERT(int, DATEDIFF(second, [DateUtc], #NOW)/60)
ORDER BY CONVERT(int, DATEDIFF(second, [DateUtc], #NOW)/60)
that has as output:
minutes_ago amount
0 4 (most recents. still being updated)
2 2
3 3
4 1
5 2
6 1
7 2
8 1
9 3