Re: Counts and percentages and such

On Tue, Dec 8, 2009 at 2:21 PM, jackassplus <jackassplus(at)gmail(dot)com> wrote:
> <snip>
>> select coalesce(col,'Null'),
>> (count(coalesce(col,'Null'))::numeric/(select count(*) from
>> some_table))*100 from some_table group by col;
>>  coalesce |        ?column?
>> ----------+-------------------------
>>  Null     | 13.33333333333333333300
>>  N        | 20.00000000000000000000
>>  A        | 26.66666666666666666700
>>  L        | 40.00000000000000000000
>>
>> Note that it works, but we get long ugly numbers, and the column has
>> no name (?column?).  Let's fix that:
>
> What does ::numeric signify?
> I'm using the jdbc driver from http://jdbc.postgresql.org/ in SQuirreL
> and it asks me for the value of :numeric.

::numeric is a cast in pgsql. The long version looks like:

cast (col as numeric)

which might work better. I'm no expert on the jdbc driver so your
question may require someone else to give a definitive answer.