Re: returning count(*) when it is > 1, else -1 - Mailing list pgsql-sql

Tom Lane wrote:
> Richard Huxton <dev@archonet.com> writes:
>> SELECT
>>   CASE WHEN total >0 THEN total ELSE -1 END AS new_total
>> FROM (
>>   SELECT count(*) AS total FROM test WHERE id=$1
>> ) AS raw_total
> 
> Actually you could just do
> 
> SELECT
>   CASE WHEN count(*) >0 THEN count(*) ELSE -1 END AS total
> FROM test WHERE id=$1;
> 
> PG has avoided redundant calculations of duplicate aggregates for some
> time.  (This doesn't help in the original formulation because it
> actually had two different sub-selects; the case that is handled is
> identical aggregate expressions within SELECT list or HAVING of a single
> SELECT.)
> 
>             regards, tom lane
> 
Thanks Tom! I like this one! It seems more readable to me.

Thank you all! Yeah, even you Achilleas bastard (no ofense) :)
Gerardo