MySQL 8.0

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CREATE TABLE users (
    id INTEGER AUTO_INCREMENT PRIMARY KEY,
    username VARCHAR(255)
);

INSERT INTO users (username) 
  VALUES 
    ('User 1'),
    ('User 2'),
    ('User 3'),
    ('User 4');
    
SELECT * FROM users;
    
CREATE TABLE message (
    id INTEGER AUTO_INCREMENT PRIMARY KEY,
    sender INTEGER NOT NULL,
    receiver INTEGER NOT NULL,
    text_message TEXT,
    created_at TIMESTAMP DEFAULT NOW(),
    FOREIGN KEY (sender)
        REFERENCES users (id)
        ON DELETE CASCADE,
    FOREIGN KEY (receiver)
        REFERENCES users (id)
        ON DELETE CASCADE
);

INSERT INTO message (sender, receiver, text_message, created_at) 
  VALUES 
    (1, 2, 'Hi User 2 part 1', CURRENT_TIMESTAMP - INTERVAL 5 MINUTE),
    (1, 3, 'Hi User 3 part 1', CURRENT_TIMESTAMP - INTERVAL 4 MINUTE),
    (1, 2, 'Hi User 2 part 2', CURRENT_TIMESTAMP - INTERVAL 3 MINUTE),
    (1, 3, 'Hi User 3 part 2', CURRENT_TIMESTAMP - INTERVAL 2 MINUTE),
    (2, 1, 'Hi User 1', CURRENT_TIMESTAMP - INTERVAL 1 MINUTE);
    
SELECT * FROM message;

id	username
1	User 1
2	User 2
3	User 3
4	User 4

id	sender	receiver	text_message	created_at
1	1	2	Hi User 2 part 1	2021-09-06 22:32:22
2	1	3	Hi User 3 part 1	2021-09-06 22:33:22
3	1	2	Hi User 2 part 2	2021-09-06 22:34:22
4	1	3	Hi User 3 part 2	2021-09-06 22:35:22
5	2	1	Hi User 1	2021-09-06 22:36:22

sendername	receivername	text_message	created_at
User 1	User 2	Hi User 2 part 2	2021-09-06 22:34:22
User 1	User 3	Hi User 3 part 2	2021-09-06 22:35:22
User 2	User 1	Hi User 1	2021-09-06 22:36:22