How to Group MySQL Timestamp Data into Custom Time Segments for Sum and Average Calculations?

Grouping Time Segments for Sum and Average Calculations

In the MySQL database, you can retrieve summarized data from a table containing timestamped records with varying intervals between captures. Your goal is to group these records and calculate sum and average values for specific time segments, such as 10 seconds or 30 seconds.

SOLUTION

The key to grouping time segments lies in the GROUP BY clause. To group and summarize data based on 30-second intervals, use the following command:

GROUP BY UNIX_TIMESTAMP(time_stamp) DIV 30

This expression divides the Unix timestamp of each record by 30, rounding down to the nearest 30-second mark. As a result, records within the same 30-second interval will be grouped together.

Customizing Time Segment Boundaries

You can modify the boundaries of your time segments by adjusting the denominator in the DIV expression. For example, to group in 20-second intervals:

GROUP BY UNIX_TIMESTAMP(time_stamp) DIV 20

Buffering Time Segments

To add a buffer to your time segments, you can use the following formula:

GROUP BY (UNIX_TIMESTAMP(time_stamp) + r) DIV 30

In this expression, r represents a non-negative integer less than 30. By adding a value to the timestamp, you can create overlapping time segments. For instance:

GROUP BY (UNIX_TIMESTAMP(time_stamp) + 5) DIV 30

This query will group records into time segments ranging from hh:mm:05 to hh:mm:35, and from hh:mm:35 to hh:mm 1:05.

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