Organization and the importance of accurate and available data

(Nicholas)To further emphasize organization and the importance of accurate and available data, primary keys are essential in the world of databases. The primary key of a relational table uniquely identifies each record in the table. Databases use keys to compare, sort, and store records, and to create relationships between records (Perian, 2021). This is a critical consideration in the design process, as you typically want to leave the key the same for the lifetime of that database as possible after assignment. Changing the primary key typically requires an alter table, as tables can only be assigned to one key at a time. Primary keys and columns that are unique to the key cannot be duplicated, so having a duplicate key is not possible, nor would it be something that would be beneficial. Natural keys hold information about facts, such as biometric data values or a social security number. An invented key and a natural key can be confused with one another, but invented keys can best be understood as non-naturally occurring values that are assigned by a database developer or generated by the system. An excellent example of an invented key is a bank account number. Because of this fact, invented keys are most common in business as generated identifiers and are typically unique to each company. Foreign keys occur when a primary key exists in different tables. Say there are two tables, Inventory, and New. NewVIN is a primary key in the New table that has the VIN number information of all new vehicles. However, the NewVIN key is referenced in the Inventory table, which has new, used, and incoming inventory information and VIN numbers. Since the NewVIN is referenced in both tables, it is a primary key to the New table and a foreign key to the Inventory table. Unlike primary keys, foreign keys can be duplicated unless the action is blocked by the database developer.