Re: count function alternative in postgres - Mailing list pgsql-sql

From Ben Morrow
Subject Re: count function alternative in postgres
Date
Msg-id 20100406184714.GA3290@osiris.mauzo.dyndns.org
Whole thread Raw
In response to count function alternative in postgres  (junaidmalik14 <junaidmalik14@gmail.com>)
Responses Re: count function alternative in postgres  (junaidmalik14 <junaidmalik14@gmail.com>)
List pgsql-sql
Quoth junaidmalik14@gmail.com (junaidmalik14):
> 
> Is there any alternative of mysql function COUNT(DISTINCT expr,[expr...]) in
> postgres. We get error if we 
> 
> write count like this count(distinct profile.id, profile.name, profile.age)
> but it works well in mysql.

Pg does support COUNT(DISTINCT ), but only for a single column. The best
I can come up with for multiple columns is
   select count(distinct profile.tuple) from       (select (id, name, age) as tuple from profile)           as
profile;

or alternatively
   select count(*) from       (select distinct (id, name, age) as tuple from profile)           as profile;

Ben



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