Non-update principles in Oracle Database Design

The non-update principle in Oracle Database Design when adding data, if the new logic involves the original information, try not to update the data. Www.2cto.com. What kind of situation will there be such a problem? For example, a user places an order. If you have purchased orders in the past, this order will be discounted, but the original order can only be discounted once at a time. A-> B-> C has two design methods. As shown in the preceding figure, orders A are at A discount based on orders B and orders B are at A discount based on orders C. Www.2cto.com first, add a Peugeot field. If yes, update this field to 1. Second, add an order field used last time, and remove it twice during query. Remove records that were not empty for the last use order, and remove data that was filled in the field of the last use order. The first query is friendly, and the second query is performance friendly. Based on the non-update principle, we chose the second method. For complex queries, we should submit them to the report library for processing.