PythonFullStackCourse/Day21/SQL/joins.sql at main · GODSROBOT/PythonFullStackCourse · GitHub

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-- INNER JOIN
SELECT s.student_name, c.course_name
FROM school.student s
INNER JOIN school.enrollments e ON s.id = e.student_id
INNER JOIN school.courses c ON e.course_id = c.course_id;


-- LEFT JOIN
SELECT s.student_name, c.course_name
FROM school.student s
LEFT JOIN school.enrollments e ON s.id = e.student_id
LEFT JOIN school.courses c ON e.course_id = c.course_id;


-- RIGHT JOIN
SELECT s.student_name, c.course_name
FROM school.student s
RIGHT JOIN school.enrollments e ON s.id = e.student_id
RIGHT JOIN school.courses c ON e.course_id = c.course_id;


-- FULL JOIN
SELECT s.student_name, c.course_name
FROM school.student s
LEFT JOIN school.enrollments e ON s.id = e.student_id
LEFT JOIN school.courses c ON e.course_id = c.course_id

UNION

SELECT s.student_name, c.course_name
FROM school.student s
RIGHT JOIN school.enrollments e ON s.id = e.student_id
RIGHT JOIN school.courses c ON e.course_id = c.course_id;