Re: count function alternative in postgres

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.

Reference url is given below

http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html#function_count-distinct

Thanks
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junaidmalik14 wrote on 03.04.2010 14:58:
>
> 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.
>
> Reference url is given below
>
> http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html#function_count-distinct
>
> Thanks

Your question has been answered several times already (including this list)

http://archives.postgresql.org/pgsql-hackers/2010-04/msg00182.php
http://archives.postgresql.org/pgsql-hackers/2010-04/msg00179.php
http://forums.devshed.com/postgresql-help-21/count-function-alternative-in-postgres-691450.html
http://www.dbforums.com/postgresql/1655165-count-function-alternative-postgres.html

Quoth junaidmalik14(at)gmail(dot)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

Thanks tkellerer.
Junaid

tkellerer wrote:
>
> junaidmalik14 wrote on 03.04.2010 14:58:
>>
>> 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.
>>
>> Reference url is given below
>>
>> http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html#function_count-distinct
>>
>> Thanks
>
> Your question has been answered several times already (including this
> list)
>
> http://archives.postgresql.org/pgsql-hackers/2010-04/msg00182.php
> http://archives.postgresql.org/pgsql-hackers/2010-04/msg00179.php
> http://forums.devshed.com/postgresql-help-21/count-function-alternative-in-postgres-691450.html
> http://www.dbforums.com/postgresql/1655165-count-function-alternative-postgres.html
>
>
>
> --
> Sent via pgsql-sql mailing list (pgsql-sql(at)postgresql(dot)org)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-sql
>
>

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Thanks Ben. It works fine.

Junaid.

Ben Morrow-2 wrote:
>
> Quoth junaidmalik14(at)gmail(dot)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
>
>
> --
> Sent via pgsql-sql mailing list (pgsql-sql(at)postgresql(dot)org)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-sql
>
>

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