Calculation of time gap between PHP, MySQL, and Oracle

PHP Strtotime ("12:25:33")-strtotime ("6:04:56"); // second gap MySQL Datediff ("D", date1, date2) // The number of days difference between the two dates "D" day "M" month "YYYY" year "H" Hour "S" second "ww" Week Date1 is the start time Date2 is the end time Time_to_sec of MySQL Select time_to_sec ("12:25:33")-time_to_sec ("6:04:56") // second gap Oracle Round (to_number (sysdate-datetime )) Round (to_number (end_date-start_date)-elapsed time (in days) Round (to_number (end_date-start_date) * 24)-elapsed time (in hours) Round (to_number (end_date-start_date) * 1440)-elapsed time (in minutes)