您可以尝试将两个时间戳相减，然后使用 to_char 提取出时间部分:

You can try just subtracting the two timestamps, then using to_char to extract out the time portion:

select
    SELECT to_char('2017-11-02 07:36:18'::timestamp -
                   '2017-11-02 05:51:10'::timestamp, 'HH:MI:SS');

输出:

to_char
01:45:08

演示