Re: simple division
От | Gavin Flower |
---|---|
Тема | Re: simple division |
Дата | |
Msg-id | fda12258-5bac-7094-39e7-4ea55c8854fb@archidevsys.co.nz обсуждение исходный текст |
Ответ на | Re: simple division (Rob Sargent <robjsargent@gmail.com>) |
Ответы |
Re: simple division
|
Список | pgsql-general |
On 05/12/2018 20:07, Rob Sargent wrote: > >> On Dec 4, 2018, at 9:33 PM, Gavin Flower <GavinFlower@archidevsys.co.nz> wrote: >> >>> On 05/12/2018 10:51, Rob Sargent wrote: >>> >>>> On 12/4/18 2:36 PM, Martin Mueller wrote: >>>> It worked, and I must have done something wrong. I'm probably not the only person who would find something like thefollowing helpful: >>>> >>>> >>>> division (integer division truncates the result) 10/3 3 >>> The math types might take offense here, with the use of "truncates". Integer division really ask how many times canone subtract the numerator from the denominator without going negative (or how many times does the numerator "go into"the denominator). >>> >>> It may seem a nuisance, but int division is a useful construct and must be supported (and be the default). (If you have10 people to transport in cars which hold four (all can drive) 10/4 = 3 ;) ) >>> >>> >>> >>> >> Hmm... >> >> 10 / 4 = 2 >> > And two are left stranded! > The point is that integer math has its place. You cant have 2.5 cars. So 10/4 in this context is 3. > More correctly the calculation is > 10/4 + 10%4>0 ? 1 :0 = 3 > > (Maybe psql does have % so mod(10,4)) > > SELECT ceil(10/4.0); Is what you want for that example.
В списке pgsql-general по дате отправления: