Content-Transfer-Encoding: 8bit
Content-Type: text/plain; charset="utf-8"
Date: Fri, 07 Dec 2007 14:22:26 +0100
From: "Stefan Scheidegger" <Stefan.Scheidegger@gmx.net>
Message-ID: <20071207132226.281710@gmx.net>
MIME-Version: 1.0
Subject: INSERT INTO relational tables
To: pgsql-sql@postgresql.org

Hi all

I'm new to SQL and I'm facing a problem I can't find any information about (google, forums). By now I wonder if I understood something wrong about relational DBs.

An example to explain my Problem:
Lets say I have a table containing information about the customer (name, address, ...) and about his order (pieces, product-name, price). Because one customer can order several products I split the table into two relational tables to prevent redundancy:

tbl_customer (cust_id, cust_name, cust_address)
and
tbl_order (ord_pieces, ord_productname, ord_price, ord_customer REFERENCES tbl_customer(cust_id))

Now I want to insert several new customers with several orders each at once. If I had all information in one table, this would be easy with something like:

INSERT INTO tbl_customerorders (name, address, pieces, porductname, price) VALUES ('MR. X', '1st street', 3, 't-shirts', 30), ('MR. X', '1st street', 5, 'books', 50),  ('MRS. Y', '2nd street', 1, 't-shirt', 10),...

But how can I do this in one query if I split the table? I can add one new customer, get his ID with curval() and then add his orders. But this won’t work if I want to add several customers at once.

To read this information I can do a query with the argument WHERE cust_id=ord_customer. I can create a VIEW doing this so I can read the data as if it was stored in only one table. But is there in posgres/sql an abstraction-layer that allows me to insert as if the information was stored in one table? (Something like a VIEW that provides INSERT, UPDATE, … and automatically inserts the referenced ID.)

Thanks for any help!
Stefan


-- 
Psssst! Schon vom neuen GMX MultiMessenger gehört?
Der kann`s mit allen: http://www.gmx.net/de/go/multimessenger