Returns the microseconds from the time or datetime expression expr as a number in the range from 0 to 999999. Returns NULL if expr is NULL.
SELECT MICROSECOND('12:00:00.123456');
123456
SELECT MICROSECOND('2019-12-31 23:59:59.000010');
10
SELECT MICROSECOND('12:00:00.123456');
123456
SELECT MICROSECOND('2019-12-31 23:59:59.000010');
10