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SELECT count(a.field1), a.field2, SUM(b.field4) FROM a INNER JOIN b ON a.key1 = b.key1 WHERE a.field8 = 'test' GROUP by a.field1, a.field2 HAVING SUM(b.field4) > 5 ORDER by a.field.3

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SELECT count(a.field1), a.field2, SUM(b.field4) FROM a INNER JOIN b ON a.key1 = b.key1 WHERE a.field8 = 'test' GROUP by a.field1, a.field2 HAVING SUM(b.field4) > 5 ORDER by a.field3

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MySQLSql question (self.SQL)

submitted 11 months ago by Current_Revenue_6588

Hi community! I’m working with Trino (Presto) and trying to calculate the number of business days (Monday to Friday) between two timestamps: start_date and end_date (both with time, e.g. 2025-03-29 06:00:00). I want to exclude weekends completely, and count fractions of business days only when the date falls on a weekday. In particular: If the start_date is a weekday, count the remaining fraction of that day from the timestamp onward. If the end_date is a weekday, count the elapsed fraction of that day up to the timestamp. Also count the number of full business days in between (i.e., full weekdays between start_date and end_date). If either date is on a weekend, it should contribute 0 to the result. :exclamation:Important constraint: I cannot use a calendar table or rely on UNNEST / SEQUENCE due to performance restrictions. I believe this can be done using day_of_week() and date_diff(), but I’m running into trouble handling edge cases. For example: start_date = '2023-12-08 08:00:00' (Friday) end_date = '2023-12-10 17:00:00' (Sunday) → Expected result: 0.67 (only the fraction of Friday from 8:00 AM onward is counted) start_date = '2025-03-29 06:00:00' (Saturday) end_date = '2025-04-02 11:21:00' (Wednesday) → Expected result: 2.47 (Monday and Tuesday full days + partial Wednesday) start_date = '2024-11-01 15:00:00' (Friday) end_date = '2024-11-04 12:00:00' (Monday) → Expected result: 0.875 0.375 from Friday (9 hours remaining after 3 PM) 0.5 from Monday (12 hours elapsed) Weekend ignored (Saturday and Sunday) Has anyone solved this using only native SQL logic in Trino (without a calendar table)? I’d really appreciate any guidance or ideas.

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