text: CREATE TABLE students (student_id VARCHAR); CREATE TABLE student_course_registrations (student_id VARCHAR) -- List the id of students who registered some courses and the number of their registered courses? SELECT T1.student_id, COUNT(*) FROM students AS T1 JOIN student_course_registrations AS T2 ON T1.student_id = T2.student_id GROUP BY T1.student_id CREATE TABLE students (student_id VARCHAR); CREATE TABLE courses (course_name VARCHAR, course_id VARCHAR); CREATE TABLE student_course_registrations (course_id VARCHAR, student_id VARCHAR) -- How many registed students do each course have? List course name and the number of their registered students? SELECT T3.course_name, COUNT(*) FROM students AS T1 JOIN student_course_registrations AS T2 ON T1.student_id = T2.student_id JOIN courses AS T3 ON T2.course_id = T3.course_id GROUP BY T2.course_id CREATE TABLE candidate_assessments (candidate_id VARCHAR, asessment_outcome_code VARCHAR) -- Find id of candidates whose assessment code is "Pass"? SELECT candidate_id FROM candidate_assessments WHERE asessment_outcome_code = "Pass" CREATE TABLE candidates (candidate_id VARCHAR); CREATE TABLE people (cell_mobile_number VARCHAR, person_id VARCHAR); CREATE TABLE candidate_assessments (candidate_id VARCHAR, asessment_outcome_code VARCHAR) -- Find the cell mobile number of the candidates whose assessment code is "Fail"? SELECT T3.cell_mobile_number FROM candidates AS T1 JOIN candidate_assessments AS T2 ON T1.candidate_id = T2.candidate_id JOIN people AS T3 ON T1.candidate_id = T3.person_id WHERE T2.asessment_outcome_code = "Fail"