using count to count values and nulls - mysql

Question

I have the query below
List the number of students graduated in 2009 by department. The results should show 0 for the departments that do not have any student graduated in 2009.
im having trouble with the 2nd part of the question. as of right now my query only shows the department that have students that graduated. i have no idea how to make the table show the departments that dd not have any students graduate.
my query looks like this
select d.name, count(s.major_id) as students from departments d
right join students s on s.major_id = d.id where extract( year from s.graduation_date ) = 2009
group by d.name
and my table looks like this
name students
Math 2
Drama 1
how can i get it to show the other departments with no students graduating?
database is
create table departments (
id integer primary key,
name varchar(255)
);
insert into departments (id, name) values (10, 'Computer Science');
insert into departments (id, name) values (20, 'Math');
insert into departments (id, name) values (30, 'Drama');
create table faculty (
id integer primary key,
name varchar(255),
department_id integer references departments(id)
);
insert into faculty (id, name, department_id) values (1, 'Turing', 10);
insert into faculty (id, name, department_id) values (2, 'Newton', 20);
insert into faculty (id, name, department_id) values (3, 'Einstein', 20);
insert into faculty (id, name, department_id) values (4, 'Brando', 30);
insert into faculty (id, name, department_id) values (5, 'Joe', 30);
insert into faculty (id, name, department_id) values (6, 'Gray', 10);
create table students (
id integer primary key,
name varchar(255),
graduation_date date,
major_id integer references departments(id)
);
insert into students (id, name, graduation_date, major_id) values
(1, 'Joe', null, 10);
insert into students (id, name, graduation_date, major_id) values
(2, 'Amy', '2009-04-22', 20);
insert into students (id, name, graduation_date, major_id) values
(3, 'Max', null, 10);
insert into students (id, name, graduation_date, major_id) values
(4, 'Sue', '2009-01-10', 20);
insert into students (id, name, graduation_date, major_id) values
(5, 'Bob', '2009-03-05', 30);
insert into students (id, name, graduation_date, major_id) values
(6, 'Kim', null, 20);
insert into students (id, name, graduation_date, major_id) values
(7, 'Art', null, 30);
insert into students (id, name, graduation_date, major_id) values
(8, 'Pat', '2005-07-11', 20);
insert into students (id, name, graduation_date, major_id) values
(9, 'Lee', null, 10);

Answer 1

Try with a LEFT JOIN instead of a RIGHT JOIN:
select d.name, count(s.major_id) as students
from departments d
left join students s on s.major_id = d.id and
extract( year from s.graduation_date ) = 2009
group by d.name
Note that extract( year from s.graduation_date ) = 2009 predicate should be placed in the ON clause, otherwise LEFT JOIN becomes an INNER JOIN.
Output:
name | students
=================+============
Computer Science | 0
Drama | 1
Math | 2