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 job_history ( employee_id number, start_date time, end_date time, job_id text, department_id number )
TABLE: CREATE TABLE regions ( region_id number, region_name text )
TABLE: CREATE TABLE departments ( department_id number, department_name text, manager_id number, location_id number )
TABLE: CREATE TABLE employees ( employee_id number, first_name text, last_name text, email text, phone_number text, hire_date time, job_id text, salary number, commission_pct number, manager_id number, department_id number )
TABLE: CREATE TABLE locations ( location_id number, street_address text, postal_code text, city text, state_province text, country_id text )
TABLE: CREATE TABLE jobs ( job_id text, job_title text, min_salary number, max_salary number )
TABLE: CREATE TABLE countries ( country_id text, country_name text, region_id number )

### Question ###
What is the minimum salary in each department?

### Accurate SQL ###

SELECT MIN(salary), department_id FROM employees GROUP BY department_id