Re: Help on (sub)-select

On Friday 20 Dec 2002 10:51 am, Philip Warner wrote:
> At 10:21 AM 20/12/2002 +0000, Gary Stainburn wrote:
> >nymr=# select r.*, s.tally from roster r,
> >nymr-# (select count(*) as tally from roster_staff where
> >nymr(# rsdate = '2002-01-01' and rsgid = 11 and rsgsid = 2) as s
> >nymr-# where rodate = '2002-01-01' and rogid = 11 and rogsid = 2;
> > rodate | rogid | rogsid | rorequired | rooptional | tally
> >------------+-------+--------+------------+------------+-------
> > 2002-01-01 | 11 | 2 | 0 | 1 | 2
> >(1 row)
>
> Try something like:
>
> select r.*, count(*) from roster r, roster_staff s
> where rsdate = rodate and rsgid = rogid and rsgsid = rogid
> group by r.*

This one came up with a parser error near '*' but I don't understand it enough
to debug it.

>
> or
>
> select r.*, (select count(*) from roster_staff s
> where rsdate = rodate and rsgid = rogid and rsgsid = rogid
> ) roster r;

This one ran, but the count column had the same value in every row - the total
count for the table.

I've managed it using an intermediate view. I've also extended it to show
everything I need - see below. I'd still like to hear from anyone who could
tell me how I can do this without the intermediate view tho'

create table roster ( -- roster definition table - holding jobs to be done
rodate date not null,
rogid int4 references diagrams(gid), -- diagram
rogsid int4 references jobtypes(jid), -- jobtype
rorequired int4, -- essential staff
rooptional int4, -- optional staff
primary key (rodate, rogid, rogsid)
);

create table roster_staff ( -- people on the roster
rsdate date not null,
rsgid int4 references diagrams(gid), -- diagram
rsgsid int4 references jobtypes(jid), -- jobtype
rssid int4 references staff(sid), -- staff id.
constraint r2 foreign key (rsdate,rsgid,rsgsid) references roster
(rodate,rogid,rogsid)
);

create view roster_tally as
select rsdate, rsgid, rsgsid, count(*) as rocount
from roster_staff group by rsdate, rsgid, rsgsid;

create view roster_details as
select r.*, coalesce(t.rocount,0) as rocount, coalesce(a.rocount,0) as
roavail
from roster r
left outer join roster_tally t on r.rodate = t.rsdate and
r.rogid = t.rsgid and
r.rogsid = t.rsgsid
left outer join roster_tally a on r.rodate = a.rsdate and
a.rsgid is null and
r.rogsid = a.rsgsid;

nymr=# select * from roster_details where rocount < rorequired and roavail >
0;
rodate | rogid | rogsid | rorequired | rooptional | rocount | roavail
------------+-------+--------+------------+------------+---------+---------
2002-01-01 | 12 | 4 | 1 | 0 | 0 | 1
(1 row)

nymr=#

>
> May not be exactly right, but you should get the idea
>
>
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--
Gary Stainburn

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