![]() Additionally, a customer's change of address would require the database manager to find all records in orders that the customer placed, and change the address data for each one.Ĭompany B is much better off with its relational database. Whenever there is duplicate data, as in the case above, many inconsistencies may arise when users try to query the database. If customers place more than one order, their general information will need to be re-entered and thus duplicated for each order they place. This means that the customer's general information, such as name and address, is stored in the same record as the order information, such as product description, quantity, and price. Because Company A has only one table of data, all the information pertaining to that order must be put into a single record. When a customer places an order with Company A, a new record (or row) in the table orders is created. Company A uses a flat file database with a single table named orders to record orders they receive, while Company B uses a relational database with two tables: orders and customers. ![]() To understand the advantages of a relational database, imagine the needs of two small companies that take customer orders for their products. ![]() Relational databases are far more flexible (though harder to design and maintain) than what are known as flat file databases, which contain a single table of data. A relational database is one that contains multiple tables of data that relate to each other through special key fields. These tables provide a systematic way of accessing, managing, and updating data. A database is a collection of data, which is organized into files called tables.
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