text: CREATE TABLE IF NOT EXISTS roles
  	( role_name VARCHAR(20) NOT NULL PRIMARY KEY
  	);
  
  INSERT INTO roles (role_name) VALUES ('user') ON CONFLICT DO NOTHING;
  
  INSERT INTO roles (role_name) VALUES ('admin') ON CONFLICT DO NOTHING;
  
  INSERT INTO roles (role_name) VALUES ('demo') ON CONFLICT DO NOTHING;
  
  