**A candidate key made up of multiple fields** In [[Relational Databases]], a Composite Key (sometimes called "Compound Key") is a [[Candidate Key]] that is comprised of more than 1 attribute. # Example Given a table with fields: - `student_id` - `first_name` - `last_name` - `is_enrolled` There are two sets of Candidate Keys. 1. `student_id` 2. `first_name`, `last_name` Since the [[Candidate Key]] `student_id` is comprised of only one attribute, it is NOT a composite key. Also, because `student_id` is not used for things other than record identification, it would be a [[surrogate keys|surrogate key]]. Since the Candidate Key `first_name`, `last_name` is comprised of more than one attribute, it is a Composite Key. **** ## Source [Database normalization - Wikipedia](https://en.wikipedia.org/wiki/Database_normalization) ## Related - [[Candidate Key]] - [[Relational Databases]]