SELECT users.username, users.user_firstname, users.user_lastname,
       users.user_role, user_events.Event_ID
FROM users
LEFT JOIN user_events ON users.id = user_events.id

SELECT users.username, users.user_firstname, users.user_lastname,
       users.user_role,
       GROUP_CONCAT(Events.Event_Name) AS Event_Names
FROM users
LEFT JOIN user_events ON users.id = user_events.id

| username    | user_firstname | user_lastname | user_role | event_id.
| M@gmail.com | jo             | mccann        | employee  | 8
| M@gmail.com | jo             | mccann        | employee  | 15

| username    | user_firstname | user_lastname | user_role | Event_Name
| M@gmail.com | jo             | mccann        | employee  | baking,run

SELECT users.username, users.user_firstname, users.user_lastname,
       users.user_role,
       GROUP_CONCAT(Events.Event_Name) AS Event_Names
FROM users LEFT JOIN
     user_events
     ON users.id = user_events.id LEFT JOIN
     Events
     ON Events.id = user_events.event_id
GROUP BY users.username, users.user_firstname, users.user_lastname, users.user_role;

SELECT users.username, users.user_firstname, users.user_lastname,
       users.user_role,
       GROUP_CONCAT(ev.Event_Name) AS Event_Names
FROM users
LEFT JOIN user_events ON users.id = user_events.id
JOIN events ev ON ev.event_id = user_events.event_id