Re: Native type for storing fractions (e.g 1/3)?

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От Ron Johnson
Тема Re: Native type for storing fractions (e.g 1/3)?
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Msg-id 45F94370.6060609@cox.net
обсуждение исходный текст
Ответ на Re: Native type for storing fractions (e.g 1/3)?  (Peter Eisentraut <peter_e@gmx.net>)
Ответы Re: Native type for storing fractions (e.g 1/3)?
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On 03/15/07 01:41, Peter Eisentraut wrote:
> Ron Johnson wrote:
>> On 03/14/07 18:55, Ken Johanson wrote:
>>> In SQL servers in general, or in PG, is there a native field type
>>> to store fractions? Or must one resort to char or separate
>>> numerator/denominator columns?
>> 1/3 repeats ad infinitum, and '1/3' would have to be converted to
>> 0.3333333333 before used in a computation, so:
>>
>> What's your ultimate purpose or goal?
>
> His goal may be to store and compute rational numbers exactly.  The
> answer is that there is no data type in PostgreSQL that supports this.
>
True.  However, with a composite type and stored procedures he could
fulfill that purpose.

CREATE TYPE ty_fraction AS
(
    n        SMALLINT,
    d           SMALLINT
);

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