Oliveiros d'Azevedo Cristina ha scritto:
> Howdy, Michelle,
>
Ciao
> for each hour it will count the number of distinct user_id's there
> are . If I understood correctly what you need...
>
> Can you please test it and see if it is OK for your needs? With me,
> it worked on the sample data you provided
>
Yes! Simply perfect!
> Best, Oliver
>
Thanks,
Michele
P.s. Have you some references about the "subquery" keyword? I found only
the word subquery as "use" (for example: select a from b where id in
(select id from table)), but not as sql command.