Modify data

The data model also makes it possible to modify the contents of the database with less chance for error. You can query the database with statements such as, Find every stock item with a manufacturer of Presta or Schraeder, and increase its price by 13 percent. You state changes in terms that reflect the meaning of the data. You do not have to waste time and effort thinking about details of fields within records in a file, so the chances for error are fewer.

The statements you use to modify stored data are covered in Modify data.