MySQL NOT NULL

When this constraint is applied, it ensures that the column is responsible for not holding NULL values.

Example

Using NOT NULL during table creation.

CREATE TABLE office (
emp_ID int NOT NULL,
emp_fName varchar(255) NOT NULL,
emp_lName varchar(255) NOT NULL,
Age int
);

Here, we created a table named office with three columns that accept non-NULL values.

Let us try uploading null values into this table and see what happens.

INSERT INTO office (emp_ID,emp_fName,Age)
VALUES(13,’Steven’,30);