Re: Insert into two tables - Mailing list pgsql-novice

From GH
Subject Re: Insert into two tables
Date
Msg-id 20010618221452.A20048@over-yonder.net
Whole thread Raw
In response to Insert into two tables  ("Robby Slaughter" <webmaster@robbyslaughter.com>)
List pgsql-novice
On Mon, Jun 18, 2001 at 04:18:57PM -0500, some SMTP stream spewed forth:
> I've got two tables, orders and order_items. orders has a primary
> key "ordersid" and order_items has a foreign key, orderid (which
> obviously references orders.ordersid)
>
> Say I want to create a new order and put some items into it. If
> I use an autoincrement field I could just:
>
>   INSERT INTO orders VALUES ( ... );
>
> And then I need to get the orderid I just created to create
> new records in the orderitems table So am I supposed to
> immediately do a:
>
>   SELECT ordersid FROM orders ORDER BY ordersid DESC LIMIT 1;

*bonk* What about the transaction that completed before you did the
select...limit?

> And then get the value, and then do inserts in the order items
> table? Surely there's some way to wrap this all up into a
> nice little procedure or something.

Er, I usually just do this:

select nextval('sequence');
insert into table(id_col) values (<nextval from above>);

That way you are guaranteed a unique sequence value.

You can also do this as:
insert into table (all_columns_except_serial) values (whatever);

> Thanks----
>
> -Robby


gh


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