What is the purpose of primary keys in a database?

Primary keys serve a crucial role in relational databases by uniquely identifying each record within a table. This uniqueness ensures that no two records can have the same primary key value, which is vital for maintaining data integrity. When each record has a distinct identifier, it allows for accurate data retrieval, updates, and management, minimizing the risk of confusion or errors that could arise from duplicate entries.

In addition to their primary function, unique identifiers can also facilitate relationships between tables. For instance, primary keys can be referenced by foreign keys in other tables, thereby establishing connections and enabling complex queries involving multiple tables. This aspect forms the backbone of relational database design, helping to enforce referential integrity and ensuring that the data remains consistent and accurate.

While sorting data alphabetically or creating backups are important operations within database management, they do not define the core purpose of primary keys. Similarly, while primary keys contribute to establishing relationships, their fundamental purpose is primarily centered around the unique identification of records within a specific table.