DB2 SQL 以 10 分钟为时间间隔的组行计数

Question

I have a table in DB2 which contains data such as the following:

completed_timestamp	details
2021-12-19-15.38.10	abcd
2021-12-19-15.39.10	efgh
2021-12-19-15.48.10	ijkl
2021-12-19-15.49.10	mnop
2021-12-19-15.54.10	qrst

I want to be able to count the number of rows in the table for every 10 minutes eg

Time	count
2021-12-19-15.40	2
2021-12-19-15.50	2
2021-12-19-16.00	1

completed_timestamp = Timestamp, details = varchar

I've seen this done in other SQL languages but so far have not figured out how to do it with DB2. How would I do that?

Answer 1

You can get the minute from the timestamp, divide it by ten, get the next integer, multiply by ten and add it to the hour as minutes:

WITH TABLE1 (completed_timestamp, details) AS (
 VALUES 
 (timestamp '2021-12-19-15.38.10', 'abcd'),
 (timestamp '2021-12-19-15.39.10', 'efgh'),
 (timestamp '2021-12-19-15.48.10', 'ijkl'),
 (timestamp '2021-12-19-15.49.10', 'mnop'),
 (timestamp '2021-12-19-15.54.10', 'qrst')
),
trunc_timestamps (time, details) AS (
  SELECT trunc(completed_timestamp, 'HH24') + (ceiling(minute(completed_timestamp) / 10.0) * 10) MINUTES, details FROM table1
)
SELECT trunc_timestamps.time, count(*) FROM trunc_timestamps GROUP BY trunc_timestamps.time