Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE users ( user_name VARCHAR, password VARCHAR, role_code VARCHAR )

### Question ###
List all the username and passwords of users with the most popular role.

### Accurate SQL ###

SELECT user_name, password FROM users GROUP BY role_code ORDER BY COUNT(*) DESC LIMIT 1