primary key
compound.compound. a unique code or piece of information used to identify one specific record in a database. Just like a passport number identifies one person, this ensures no two rows of data are exactly the same.
compound. a specific column or set of columns in a database table that uniquely identifies each row. It must contain unique values and cannot contain null entries, ensuring data integrity and allowing for efficient record retrieval.
The student ID serves as the primary key for the database.
When designing the customer table, the developer assigned a unique serial number as the primary key to prevent duplicate entries.
In relational database design, the primary key is essential for establishing relationships with other tables, where it is referenced as a foreign key to maintain referential integrity across the system.
A compound of the adjective primary, denoting first importance or rank, and the noun key, used in the cryptographic and mechanical sense of a device that provides access or unlocks a specific result.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.
Often used in the context of SQL and relational database management systems (RDBMS).
Last updated July 22, 2026