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 employees (first_name VARCHAR, last_name VARCHAR, department_id VARCHAR, salary INTEGER)

### Question ###
Find the first name and last name and department id for those employees who earn such amount of salary which is the smallest salary of any of the departments.

### Accurate SQL ###

SELECT first_name, last_name, department_id FROM employees WHERE salary IN (SELECT MIN(salary) FROM employees GROUP BY department_id)