What is a primary key in a database?

What is a primary key in a database?

A primary key is a unique identifier for a record in a database table, ensuring that each entry is distinct.

Why is it important to have a primary key?

It ensures data integrity by preventing duplicate records and allows for efficient data retrieval.

Can a primary key be null?

No, a primary key must always have a value; it cannot be null.

What are some examples of primary keys?

Common examples include user IDs, email addresses, or any unique identifier for a record.

How do I choose a good primary key?

A good primary key should be unique, stable, and not change over time, like a serial number.