Time difference between two date fields

I have a date field names “dts” in string format. I want to find out all the records based on their time differences (in hours). The run event time should be greater than or equal to eat event.

The output should be:

Answer

Convert timestamps to seconds, then subtract, divide result by 3600 to get hours, use case+count to count by ranges, something like this:

select count(case when diff_hrs >24 then 1 end) as more_24,
       count(case when diff_hrs <=24 then 1 end) as less_than_24,
       ...
       count(case when diff_hrs >=2 and diff_hrs <=3 then 1 end) as hrs_2_to_3,
       ...
from
(
select
abs(unix_timestamp(dts) - unix_timestamp(dts-eat)))/60/60 as diff_hrs
from table
)s;