From: Viorel Dragomir <bigchief@vio.ro>
To: pgsql-sql@postgresql.org
Subject: Re: summing tables
Date: Tue, 15 Jul 2003 15:16:21 +0300
Message-ID: <001501c34aca$e70ca280$0600a8c0@fix.ro> (raw)
References: <20030715140921.7c5a6a6c.erik@thiele-hydraulik.de>
update table_name
set c = a + b + (select c from table_name as x where x.seq = seq-1)
where c is null;
additional checks are required if you want to update c when c is not null
if all the c are null then this query will do nothing
god help u
:)
----- Original Message -----
From: "Erik Thiele" <erik@thiele-hydraulik.de>
To: <pgsql-sql@postgresql.org>
Sent: Tuesday, July 15, 2003 3:09 PM
Subject: [SQL] summing tables
> hi,
>
> i have a table consisting of 4 integers.
>
> seq is for making the table ordered. (ORDER BY SEQ ASC)
> a,b,c maybe null
>
>
> seq | a | b | c
> -----+----+----+---
> 0 | 1 | 2 | 3
> 1 | 1 | 2 |
> 2 | 5 | 7 |
> 3 | -2 | -4 |
>
>
> i am needing a sql statement to do
>
> c=a+b+"the c of the row with seq one less than myself"
>
> this statement has to run over the whole table, in seq order.
>
>
> how can this be acomplished???
>
>
> cu&thanks
> erik
>
>
> --
> Erik Thiele
>
> ---------------------------(end of broadcast)---------------------------
> TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-sql@postgresql.org
Cc: bigchief@vio.ro
Subject: Re: summing tables
In-Reply-To: <001501c34aca$e70ca280$0600a8c0@fix.ro>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox