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 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 Courses (course_id NUMBER, author_id NUMBER, subject_id NUMBER, course_name VARCHAR2, course_description VARCHAR2)
CREATE TABLE Subjects (subject_id NUMBER, subject_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 Student_Tests_Taken (registration_id NUMBER, date_test_taken DATETIME, test_result VARCHAR2)

A bar chart for finding the number of the dates of the tests taken with result 'Pass', sort Y-axis in descending order.
SELECT date_test_taken, COUNT(date_test_taken) FROM Student_Tests_Taken WHERE test_result = "Pass" GROUP BY date_test_taken ORDER BY COUNT(date_test_taken) DESC
SELECT "date_test_taken", COUNT("date_test_taken") FROM "Student_Tests_Taken" WHERE "Pass" = "test_result" GROUP BY "date_test_taken" ORDER BY COUNT("date_test_taken") DESC