Re: help me...

That's what I said! :)
Yasir

On Sun, 9 Nov 2003, Christopher Browne wrote:

> Date: Sun, 09 Nov 2003 21:59:14 -0500
> From: Christopher Browne <cbbrowne@acm.org>
> To: pgsql-sql@postgresql.org
> Subject: Re: [SQL] help me...
>
> The world rejoiced as ron_tabada@yahoo.com (ron_tabada) wrote:
> > Hello everyone, Good day! Could anyone help me translate this query
> > in Microsoft Access to Postgresql. I'm having a difficulty. Pls...
> >
> > Query1:
> > SELECT items.description, Sum(supplieditems.qty) AS SumOfqty
> > FROM items INNER JOIN supplieditems ON items.itemno = supplieditems.itemno
> > GROUP BY items.description;
> >
> > Query2:
> > SELECT [items].[description], Sum([customer].[qty]) AS SumOfqty
> > FROM (items INNER JOIN OtherItem ON [items].[itemno]=[OtherItem].[Itemno]) INNER JOIN customer ON
> > [OtherItem].[Itemno]=[customer].[itemcode]
> > GROUP BY [items].[description];
> >
> > Query3:
> > SELECT [Query1].[SumOfqty], [Query2].[SumOfqty], [Query1]![SumOfqty]-[Query2]![SumOfqty] AS remain
> > FROM Query1, Query2;
> >
> > I have translated Query1 and Query2 in POSTGRESQL but I don't know
> > how to implement Query3.
>
> Apparently you have discovered the nearest equivalent to "VIEWs" in
> Access.
>
> I can suggest two ways:
>
> 1.  Define "query1" and "query2" as PostgreSQL views, as with...
>
>   create view query1 as
>      SELECT items.description, Sum(supplieditems.qty) AS SumOfqty
>      FROM items INNER JOIN supplieditems ON items.itemno = supplieditems.itemno
>      GROUP BY items.description;
>
>   create view query2 as [omitted details].
>
>   Query 3 should work perfectly well when it has the two views to work
>   with.
>
> 2.  Subselects...
>
>  SELECT Query1.SumOfqty, Query2.SumOfqty, Query1.SumOfqty-Query2.SumOfqty AS remain
>  FROM
>     (select stuff for query 1) as query1,
>     (select stuff for query 2) as query2;
>
> Approach #1. seems more appropriate, as it uses the views to keep the
> queries all simple.
> --
> let name="cbbrowne" and tld="acm.org" in String.concat "@" [name;tld];;
> http://www.ntlug.org/~cbbrowne/nonrdbms.html
> Incrementally extended heuristic algorithms tend inexorably toward the
> incomprehensible.
>
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