CREATE TABLE Student_Course_Registrations (student_id NUMBER, course_id NUMBER, registration_date DATETIME)
CREATE TABLE Candidates (candidate_id NUMBER, candidate_details VARCHAR2)
CREATE TABLE Courses (course_id VARCHAR2, course_name VARCHAR2, course_description VARCHAR2, other_details VARCHAR2)
CREATE TABLE Candidate_Assessments (candidate_id NUMBER, qualification CHAR, assessment_date DATETIME, asessment_outcome_code CHAR)
CREATE TABLE Addresses (address_id NUMBER, line_1 VARCHAR2, line_2 VARCHAR2, city VARCHAR2, zip_postcode CHAR, state_province_county VARCHAR2, country VARCHAR2)
CREATE TABLE Students (student_id NUMBER, student_details VARCHAR2)
CREATE TABLE People (person_id NUMBER, first_name VARCHAR2, middle_name VARCHAR2, last_name VARCHAR2, cell_mobile_number VARCHAR2, email_address VARCHAR2, login_name VARCHAR2, password VARCHAR2)
CREATE TABLE Student_Course_Attendance (student_id NUMBER, course_id NUMBER, date_of_attendance DATETIME)
CREATE TABLE People_Addresses (person_address_id NUMBER, person_id NUMBER, address_id NUMBER, date_from DATETIME, date_to DATETIME)

Give me a bar graph for what is the total number of last names of all candidates?, sort in asc by the x axis.
SELECT last_name, COUNT(last_name) FROM People GROUP BY last_name ORDER BY last_name
SELECT "last_name", COUNT("last_name") FROM "People" GROUP BY "last_name" ORDER BY "last_name"