What is a composite key?

How does it differ from a primary key?

A composite key is a combination of two or more columns in a table that can uniquely

identify each record in the table. It is used when a single column is not sufficient to uniquely

identify a row.

• Composite Key: Consists of multiple columns.

Example: A table storing student-course enrollments might use a composite key

consisting of StudentID and CourseID to uniquely identify each enrollment record.

• Primary Key: A primary key is a single column (or a composite of columns) that

uniquely identifies each record in a table. It can be a single column or a composite

of multiple columns, but it must be unique for each row.