From: | Brian Hurt <bhurt(at)janestcapital(dot)com> |
---|---|
To: | Tore Lukashaugen <tore(at)lukashaugen(dot)freeserve(dot)co(dot)uk> |
Cc: | pgsql-novice(at)postgresql(dot)org |
Subject: | Re: Simple sql question |
Date: | 2007-10-03 18:43:43 |
Message-ID: | 4703E2DF.6010409@janestcapital.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-novice |
Tore Lukashaugen wrote:
>Hello,
>
>I am new to Postgres and have an embarassingly simple question. I am running
>v8.2 on Windows Vista although I don't think that has any bearing on the
>answer.
>
>create table test (col1 int, col2 int)
>insert into test values (1,2);
>select col1/col2 from test....yields 0 not 0.5 - why?
>
>Presumably this is because both col1 and col2 are ints and the output needs
>to be casted somehow? Or is it because PGAdmin's SQL interface does not by
>default show the decimal places of output?
>
>Appreciate your help.
>
>Tore
>
>
It's because they're ints, and integer division rounds down (for
positive integers- I forget what the rule is if one or both integers are
negative). You can cast one (probably t1) to numeric to get the
fractional part, like:
> bhurt2_dev=# create table test (col1 int, col2 int);
> CREATE TABLE
> bhurt2_dev=# insert into test values (1,2);;
> INSERT 0 1
> bhurt2_dev=# select col1::numeric/col2 from test;
> ?column?
> ------------------------
> 0.50000000000000000000
> (1 row)
>
> bhurt2_dev=#
Brian
From | Date | Subject | |
---|---|---|---|
Next Message | Tom Lane | 2007-10-03 18:44:39 | Re: Simple sql question |
Previous Message | Sean Davis | 2007-10-03 18:38:24 | Re: Simple sql question |