BUG #3959: Huge calculation error

Renaud Diez wrote:

The following bug has been logged online:

Bug reference: 3959
Logged by: Renaud Diez
Email address: rdiez@salesprize.com
PostgreSQL version: 8.2
Operating system: Debian
Description: Huge calculation error
Details:

the basic mathematical expression like the following one doesn't compute the
correct result:

select 100*(1+(21/100));

return a result of 100 instead of 121.

It does compute the correct result, because you're doing integer
calculations. 21/100 for integers is 0. To make it do float calc, you can do
select 100*(1+(21::float/100));

Or you can do
select 100*(1+(21.0/100));

which will force it to numeric.

//Magnus

Renaud Diez wrote:

The following bug has been logged online:

Bug reference: 3959
Logged by: Renaud Diez
Email address: rdiez@salesprize.com
PostgreSQL version: 8.2
Operating system: Debian
Description: Huge calculation error
Details:

the basic mathematical expression like the following one doesn't compute the
correct result:

select 100*(1+(21/100));

return a result of 100 instead of 121.

That's because 21/100 = 0, in integer math. Try "SELECT
100*(1+(21/100.0))" to use floating points.

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com

Renaud Diez wrote:

The following bug has been logged online:

Bug reference: 3959
Logged by: Renaud Diez
Email address: rdiez@salesprize.com
PostgreSQL version: 8.2
Operating system: Debian
Description: Huge calculation error
Details:

the basic mathematical expression like the following one doesn't compute the
correct result:

select 100*(1+(21/100));

return a result of 100 instead of 121.

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Hola, en realidad no lo hace mal, no es lo que esprabas, lo que en
realidad necesitas es esto:
select 100*(1+(21.0/100))::float;
saludos Fernando