Query help with round up of dates

Question

Hi,
I have a problem with my query.
I am calculating the difference between two dates and I want to get the hours.
The problem is that I want the following to happen:
if the difference is x such that x > 0 it should round it up to 1 (example: x = 0.1 it should be rounded up to 1)
if the difference is y such that y >1 it should be rounded to 1 (example y = 1.05 it should be rounded up to 2)
i have the following query at the momet:
select to_char(arrivaldate,'DD/MM/YYYY hh24:mi:ss') as "ARRIVAL", to_char(departuredate,'DD/MM/YYYY hh24:mi:ss') as "DEPARTURE", round(trunc(mod((departuredate-arrivaldate)*24,24),2)) as duration from stay_log;
thanks.

Answer 1

Hi,
Format your code so that the physical appearance of the code gives some hint as to what you're doing, as I did below.
When posting code on this forum, always type {code} tags at the beginning and end of formatted sections.
Do you mean that, instead of 21, you want to use the flightid from the main query?
If so, that's called a "correllated query". The tables in the main query (and their columns) can be reference in the sub-query, like this:
select     flightid                         as "FLIGHT",
          select     destairport_id
          from     journey,
               flight
          where     flight.flightid  = stay_log.flight_id   -- correlated to main query
          and     flight.journeyid = journey.journeyid
     )                              AS "AIRPORT",
     to_char(arrivaldate,'DD/MM/YYYY hh24:mi:ss')     as "ARRIVAL",
     to_char(departuredate,'DD/MM/YYYY hh24:mi:ss')     as "DEPARTURE",
     ceil((departuredate-arrivaldate)*24)          as "DURATION",
     cost                              as "COST"
from     stay_log;Often, people give a table alias to the main query table that is being referenced in the sub-query, as shown below.
That's only required when the table name appears in both FROM-clauses.
select     flightid                         as "FLIGHT",
          select     destairport_id
          from     journey,
               flight
          where     flight.flightid  = s.flight_id     -- table alias s used here
          and     flight.journeyid = journey.journeyid
     )                              AS "AIRPORT",
     to_char(arrivaldate,'DD/MM/YYYY hh24:mi:ss')     as "ARRIVAL",
     to_char(departuredate,'DD/MM/YYYY hh24:mi:ss')     as "DEPARTURE",
     ceil((departuredate-arrivaldate)*24)          as "DURATION",
     cost                              as "COST"
from     stay_log   s     -- table alias s defined here
;