Re: Postgresql problem with update double precision - Mailing list pgsql-general

From Jerry Sievers
Subject Re: Postgresql problem with update double precision
Date
Msg-id 8739hgcdge.fsf@comcast.net
Whole thread Raw
In response to Postgresql problem with update double precision  (Condor <condor@stz-bg.com>)
Responses Re: Postgresql problem with update double precision
List pgsql-general
Condor <condor@stz-bg.com> writes:

> Hello ppl,
> for few years I have problem when update double precision field. I
> have table and few double precision columns, here is example:
>
> sumall double precision,
> sumin double precision,
>
> My php script do:
>
> $get = 2.40
>
> and sql code is:
>
> UPDATE table1 SET sumall = sumall + $get WHERE id = 1 AND rd =
> CURRENT_DATE;
>
>
> When I browse the table some times i see incorrect values like:
>
> 955.599999999998
>
> it's should be 955.60 after these updates ... some days is fine, some
> days the value is incorrect.
>
> I have this problem from version 7 of postgresql, Im now use 9.0.3
>
> Anyone know what can be the problem and why some times records is
> fine, some times isnt ?

That floating point data types are inexact is a well known problem
with them and not Postgres specific.

Consider switching those fields to type NUMERIC.

HTH
>

--
Jerry Sievers
Postgres DBA/Development Consulting
e: postgres.consulting@comcast.net
p: 305.321.1144

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