What are some examples of composite keys in databases?

What are some examples of composite keys in databases?

Composite keys are made up of two or more columns in a table that uniquely identify a row. For example, in a table of student enrollments, a composite key could be a combination of 'student_id' and 'course_id'.

Can you give me another example?

Sure! In an orders table, a composite key might consist of 'order_id' and 'product_id' to uniquely identify each product in an order.

Why would I use a composite key instead of a single primary key?

Composite keys are useful when a single column isn't unique enough to identify a record. They help maintain data integrity by ensuring that the combination of values is unique.

Are there any drawbacks to using composite keys?

Yes, composite keys can complicate queries and indexing. They may also make foreign key relationships more complex.