From: Jasen Betts <jasen@xnet.co.nz>
To: pgsql-sql@postgresql.org
Subject: Re: multi table import from 1 denormalized source table
Date: 16 Nov 2010 08:21:46 GMT
Message-ID: <ibteuq$dl9$3@reversiblemaps.ath.cx> (raw)
References: <4CE21D4A.4070200@gmx.net>
On 2010-11-16, Andreas <maps.on@gmx.net> wrote:
> Hi,
>
> I frequently get tables from spreadsheets to import into the DB.
>
> Usually it looks like this:
> A1, A2, A3, A4, B1, B2, B3, with optional C1, C2, D1, D2, ...
>
> and there is a 1:n relation between A and B.
> If provieded the C would be 1:1 to A and D 1:1 to B.
>
> Up until now I let a VBA script order the source table by A, then scan
> the table line by line and create a new entry in the target table A* and
> fetch its serial ID everytime the script figures that A changed.
> With this IDa create 1 C* and as many B*s until A changes again ... and
> of course fetch IDb to attach the D* records with a foreign key column.
>
> Now I'm trying to get away w/o the VBA stuff.
>
> Is there a clever way to split such denormalized sources while still
> obtaining the needed IDs to connect everything?
create a temporary table and put the IDS in there.
then do a select distinct to populate table B,
do an update from to put the IDs from B into the temp table
then do a select to populate table A
etc...
--
⚂⚃ 100% natural
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-sql@postgresql.org
Cc: jasen@xnet.co.nz
Subject: Re: multi table import from 1 denormalized source table
In-Reply-To: <ibteuq$dl9$3@reversiblemaps.ath.cx>
* 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