Обсуждение: SELECT DISTINCT and count(1)

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SELECT DISTINCT and count(1)

От
A B
Дата:
Hi.
I need to do a

select distinct userid  from  usertable,<more tables>  where <conditions>;

and then count the rows in the result

How do I do that?

Re: SELECT DISTINCT and count(1)

От
A B
Дата:
Thank you both for both for your replies.

2009/7/16 Maximilian Tyrtania <maximilian.tyrtania@onlinehome.de>:
> am 16.07.2009 11:57 Uhr schrieb A B unter gentosaker@gmail.com:
>
>> Hi.
>> I need to do a
>>
>> select distinct userid  from  usertable,<more tables>  where <conditions>;
>>
>> and then count the rows in the result
>>
>> How do I do that?
>
> Try:
>
> select count(distinct(userid))  from  usertable,<more tables>  where
> <conditions>;
>
> Best wishes from Berlin,
>
> Maximilian Tyrtania
>
>
>

Re: SELECT DISTINCT and count(1)

От
nobs@nobswolf.info (Emil Obermayr)
Дата:
On Thu, Jul 16, 2009 at 11:57:56AM +0200, A B wrote:
>
> select distinct userid  from  usertable,<more tables>  where <conditions>;
>
> and then count the rows in the result

make it a subselect and count in the outer select:

select count(*) as num from (select distinct...) dummy;