What is the difference between an index and a primary key in SQL?

What is the difference between an index and a primary key in SQL?

A primary key uniquely identifies each record in a table, while an index improves the speed of data retrieval.

Can a primary key have duplicates?

No, a primary key must contain unique values and cannot have duplicates.

What happens if I try to insert a duplicate primary key?

If you try to insert a duplicate primary key, the database will return an error and reject the insertion.

Can an index be created on a primary key?

Yes, a primary key automatically creates a unique index on the column(s) defined as the primary key.

Are there different types of indexes in SQL?

Yes, there are several types of indexes, including unique indexes, composite indexes, and full-text indexes.