Column definitions

Learn to give a column name and type.

PRIMARY KEY

With PRIMARY KEY you make a column the primary key. Its value is unique and cannot be null.

CREATE TABLE products (
  id INT PRIMARY KEY,
  name VARCHAR(100)
);

Id is the primary key; unique and not null.

The table products is created.

Each table has at most one primary key. It creates an index automatically. It is usually given to the id column.

Create customers with id INT PRIMARY KEY and name VARCHAR(100).

Show example solution

CREATE TABLE customers (
  id INT PRIMARY KEY,
  name VARCHAR(100)
)

Primary key

CREATE TABLE products (
  id INT ____,
  name VARCHAR(100)
);

Show answer

CREATE TABLE products (
  id INT PRIMARY KEY,
  name VARCHAR(100)
);

Next lesson: NOT NULL