title: How to construct a command to join 3 different tables in mySQL?
body: <p>I have three different tables in MySQL:</p>
  
  <p><img src="https://i.imgur.com/egR9s.jpg?1" alt=""></p>
  
  <p>given an user id, how can i get a list of role's name of this user?
  For example, user_id = 1
  I need a list like this (1, deleteuser, modifyuser, viewuser)</p>
  
  <p>How can I construct my SQL command to get such a list?</p>