Re: count function alternative in postgres

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