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Asked: 2026-06-15T22:37:32+00:00

I have a MySql table with sample data like this: +———+———+——–+———————+ | id |

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I have a MySql table with sample data like this:

+---------+---------+--------+---------------------+
|      id | user_id | scores |          created_at |
+---------+---------+--------+---------------------+
|       1 |       1 |     10 | 2012-12-14 02:40:37 |
|       2 |       1 |     20 | 2012-12-14 02:55:54 |
|       3 |       1 |     10 | 2012-12-14 01:17:21 |
|       4 |       2 |     30 | 2012-12-13 01:54:47 |
|       5 |       2 |     55 | 2012-12-15 00:34:39 |
|       6 |       2 |     10 | 2012-12-14 00:20:21 |
+---------+---------+--------+---------------------+

And I need to query it, so that scores would be summed per user and per hour. One hour here is assumed to be created_at with skipped minutes and seconds (04:00:00 to 04:59:59 etc.). So something like this:

+---------+--------+---------------------+
| user_id | scores |          created_at |
+---------+--------+---------------------+
|       1 |     30 | 2012-12-14 02:00:00 |
|       1 |     10 | 2012-12-14 01:00:00 |
|       2 |     30 | 2012-12-13 01:00:00 |
|       2 |     55 | 2012-12-15 00:00:00 |
|       2 |     10 | 2012-12-14 00:00:00 |
+---------+--------+---------------------+

In this sample data only first user played more than once during one hour (2012-12-14 02:00:00) – so his scores during that hour were summed up.

From summed scores I need only top score for each user (to create ranks). So final, expected result should be:

+---------+---------------------+---------------------+
| user_id | top_scores_per_hour |                hour |
+---------+---------------------+---------------------+
|       1 |                  30 | 2012-12-14 02:00:00 |
|       2 |                  55 | 2012-12-15 00:00:00 |
+---------+---------------------+---------------------+

I have an Idea how to do part of this… I could deal with rest outside of database, but I really wonder – how could I query this with SQL ?

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1 Answer

  1. Editorial Team
    SELECT a.user_id,
       a.totalScores top_scores_per_hour,
       a.newTime hour
FROM
    (
      SELECT  user_id, 
              SUM(Scores) totalScores, 
              DATE_Format(created_at, '%Y-%m-%d %H:00:00') newTime
      FROM    TableName 
      GROUP BY user_id, DATE_Format(created_at, '%y-%m-%d %H:00:00')
    ) a INNER JOIN 
    (
      SELECT  user_id, 
              max(DATE_Format(created_at, '%Y-%m-%d %H:00:00')) newTime
      FROM    TableName 
      GROUP BY user_ID
    ) b ON a.user_ID = b.user_ID AND
           a.newTime = b.newTime

    Output

    ╔═════════╦═════════════════════╦═════════════════════╗
║ USER_ID ║ TOP_SCORES_PER_HOUR ║        HOUR         ║
╠═════════╬═════════════════════╬═════════════════════╣
║       1 ║                  30 ║ 2012-12-14 02:00:00 ║
║       2 ║                  55 ║ 2012-12-15 00:00:00 ║
╚═════════╩═════════════════════╩═════════════════════╝
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