This isn't very hard. Is this for some class assignment? I'll sketch out the
query logic for you.
- Join the tables by code_object
- Constrain the rows to those having date_event between date_in and
date_out
- Count the constrained rows grouping by code_object
"gil guerillot" <gil.guerillot_at_ratp.fr> wrote in message
news:aarbt8$fuv$1_at_gotix.reseau.ratp...
>
>
> i have 2 tables:
>
> (table objects: code_object,date_in,date_out)
> (table events:code_event,date_event,code_object)
>
> join by code_object
>
> i' d like to know the number of events by object and by year.
>
> but i must count only the event when the object is there at the event
> date(between date_in and date_out)
>
> how can i do with SQL ?
>
>
Received on Thu May 02 2002 - 08:30:13 CDT
