What is a primary key in MySQL?

A primary key is a column (or group of columns) that uniquely identifies each row. It cannot be NULL and cannot repeat. A table can have only one primary key.

CREATE TABLE students (
  id INT AUTO_INCREMENT PRIMARY KEY,
  name VARCHAR(50) NOT NULL
);

A primary key also gets an index automatically, so searches by it are fast. See MySQL Constraints.

• Previous Interview Question
• Next Interview Question

---

Tutorials
No Content Found.

Exercises & Assignments
No Content Found.

Interview Questions & Answers
No Content Found.