mysql 求时间的绝对差 timediff 有坑

SELECT TIMEDIFF(“00:00:03”, “00:00:02”);
结果00:00:01

SELECT TIMEDIFF(“00:00:03”, “00:00:02”);
结果也是00:00:01

但是跨天又正常了

SELECT timediff(‘2010-01-01 01:00:00’, ‘2010-01-02 01:00:00’);
-24:00:00