Re: Re: PostgreSQL needs percentage function

On Tue, Dec 19, 2017 at 4:54 AM, Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
wrote:

>
>
> 2017-12-19 10:13 GMT+01:00 Nick Dro <postgresql(at)walla(dot)co(dot)il>:
>
>> This is exactly why I think there should be some build-in function for
>> that...
>> Percentage calculation exists in almost any databse and information
>> system - it requires from use to implement many functions on thier own for
>> something that is very basic.
>> The general idea of my request is that postgresql should have build in
>> function for percentage calculation it doesn't have to me the exact example
>> I gave. Any thing will be better than none.
>>
>
> I don't agree - there is not compatibility or portability reasons. The
> calculation using numeric operators is pretty simple, and possibility to
> create own function is here too.
>
> So there is not any reason to increase a postgresql catalogue.
>
> Please. don't do top post
>
> Regards
>
> Pavel
>
>
>>
>>
>>
>> ב דצמ׳ 18, 2017 18:28, Michael Nolan כתב:
>>
>>
>>
>> On Mon, Dec 18, 2017 at 6:23 AM, Nick Dro <postgresql(at)walla(dot)co(dot)il >
>> wrote:
>>
>> Hi,
>> Why PostgreSQL doesn't have build-in function to calculate percentage?
>> somthing like percent(number,%
>> for example:
>> select percent(100,1) will calculate 1% of 100 = 1
>> select percent(25,20) will calculate 20% of 25 = 5
>>
>> Seems like a nice addition to the math functions list:
>> https://www.postgresql.org/docs/9.5/static/functions-math.html
>>
>> This is veryhelpull function, many uses percentage calculation in thier
>> work and it will simplify the process. Percentage calculation is considered
>> a basic math operation and I think postgresql should support it as a
>> build-in function.
>> Seems like easy to implment isn't it?
>>
>>
>> It's a bit trickier than that, because you';ll have to deal with
>> integers, real, double precision, etc. You may also want to deal with null
>> values. I found it more useful to write a function that displays X as a
>> percentage of Y, rounded to 1 digit to the right of the decimal point.
>> --
>> Mike Nolan
>>
>>
>
>Percentage calculation exists in almost any databse and information system

That is not exactly true. AFAIK, only Oracle has a Percentage function. SQL
Server and MySQL do not.
It has already been shown that it is just as easy to code percentage
inline (EG: SELECT (50.8 x 5.2) / 100 AS pct; ## .026416
as it is to call a function SELECT pct(50.8, 5.2);
Please do not false statements to justify a request for a non-needed
enhancement.

--
*Melvin Davidson*
I reserve the right to fantasize. Whether or not you
wish to share my fantasy is entirely up to you.