Re: Table Updates ..
От | Rudi Starcevic |
---|---|
Тема | Re: Table Updates .. |
Дата | |
Msg-id | 3E6EB296.4020800@oasis.net.au обсуждение исходный текст |
Ответ на | Table Updates .. (Rudi Starcevic <rudi@oasis.net.au>) |
Список | pgsql-sql |
Josh, Thanks for that. You're suggestion is how I currently have it. However some other's had doubted my method and suggested the logging table(s). Keeping is simple is much better. Thanks again. Regards Rudi. Josh Berkus wrote: >Rudi, > > > >>If I have 3 tables : >> >>orders, >>products, >>orders_products ( join table for orders and products ) >> >>If I insert an order with two products I have: >> >>2 rows in the products table, ( the two products ) >>1 row in the orders table and ( one order ) >>2 rows in the orders_products table. ( two products for this order ) >> >>So far so good. All that works well. >>But what if next week one the the products in the products table is >>updated and changed ? >>Then my order from last week is now different -- corrupted. It links to >>the same product_id but the product is changed. >> >> > >If you're concerned with "freezing" the product characteristics at the time of >the order, the answer is to add all or most of the columns in the products >table to orders_products. Then, at the time of order finalization >(shipping? not sure) you copy those columns from products to order_products. > >If you're into ORDMBS, you could even create orders_products as inheriting >products. But this isnt' required. > >This will work better than a monthly log. > > >
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