CREATE TABLE Course_Authors_and_Tutors (author_id NUMBER, author_tutor_ATB VARCHAR2, login_name VARCHAR2, password VARCHAR2, personal_name VARCHAR2, middle_name VARCHAR2, family_name VARCHAR2, gender_mf VARCHAR2, address_line_1 VARCHAR2)
CREATE TABLE Courses (course_id NUMBER, author_id NUMBER, subject_id NUMBER, course_name VARCHAR2, course_description VARCHAR2)
CREATE TABLE Students (student_id NUMBER, date_of_registration DATETIME, date_of_latest_logon DATETIME, login_name VARCHAR2, password VARCHAR2, personal_name VARCHAR2, middle_name VARCHAR2, family_name VARCHAR2)
CREATE TABLE Student_Course_Enrolment (registration_id NUMBER, student_id NUMBER, course_id NUMBER, date_of_enrolment DATETIME, date_of_completion DATETIME)
CREATE TABLE Subjects (subject_id NUMBER, subject_name VARCHAR2)
CREATE TABLE Student_Tests_Taken (registration_id NUMBER, date_test_taken DATETIME, test_result VARCHAR2)

Find the number of courses for each subject in a bar chart, and order total number in desc order.
SELECT subject_name, COUNT(*) FROM Courses AS T1 JOIN Subjects AS T2 ON T1.subject_id = T2.subject_id GROUP BY T1.subject_id ORDER BY COUNT(*) DESC
SELECT "subject_name", COUNT(*) FROM "Courses" "T1" JOIN "Subjects" "T2" ON "T1"."subject_id" = "T2"."subject_id" GROUP BY "T1"."subject_id" ORDER BY COUNT(*) DESC