How do I subtract using SQL in MYSQL between two date time values and retrieve the result in minutes or seconds?

Precision, thy name is TIMEDIFF() and TIME_TO_SEC()

Give the clock maker a run for his money. Use TIMEDIFF() for time subtraction, and TIME_TO_SEC() to squeeze the difference into seconds.

-- A ticking clock has nothing on this!
SELECT TIME_TO_SEC(TIMEDIFF(end_time, start_time)) AS second_difference from my_table_of_time;
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Users, users, where are thou users?

Catch your users, based on timeframe. Flex the power of TIMESTAMPDIFF() with the WHERE clause.

-- Who was here in the last half-hour? Let's see!
SELECT user_id, TIMESTAMPDIFF(MINUTE, last_login, NOW()) AS minutes_past 
FROM users
WHERE TIMESTAMPDIFF(MINUTE, last_login, NOW()) < 30;
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Edge cases: the SQL developer's final frontier

Dealing with time zone differences or daylight saving time shifts? Test, test, and test again. Arm your queries with robustness.

Enter TIMESTAMPDIFF(): A performance beast

Working with larger datasets? Need speed? Make TIMESTAMPDIFF() your partner in time.

-- Converting coffee into code since 1995
SELECT user_id, TIMESTAMPDIFF(SECOND, start_datetime, end_datetime) AS seconds_interval
FROM user_sessions
WHERE start_datetime BETWEEN '2023-01-01' AND '2023-01-31';
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Indexes on start_datetime and end_datetime — the stuff of legends.

Military time: Friend or Foe?

Working with military time (24-hour clock)? Beware the negative values. Always confirm if your start time is later in the day than the end time on the previous day. No one wants their time travel adventure to end in a blackhole.