I have a table in phpMyAdmin with some existing data:

CREATE TABLE users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    username VARCHAR(50),
    email VARCHAR(100)
);

Currently, the email column allows NULL values. I want to change it to NOT NULL.

But before applying, I wanted to check if this operation deletes or overwrites any of my existing data. I just want to confirm the exact behaviour in phpMyAdmin before making the change.