Joining Three Tables

This lesson covers joining three or more tables together, so you can pull data out of a deeply normalized database. It's for anyone searching "SQL multiple table JOIN."

JOIN can be chained more than once — combining "students," "classes," and "teachers" tables into one unified result is entirely normal.

The example joins students, classes, and teachers using two JOINs in a row. It reads more clearly if you think of it as "the second JOIN builds on the result of the first" — one step at a time.

A common early mistake is losing track of which table a column belongs to as JOINs stack up — writing table.column explicitly, even when it's not strictly required, keeps a complex query readable and avoids confusion. Real databases routinely split information across many tables through normalization, so combining several JOINs to reassemble everything you need into one table is a foundational skill you'll rely on constantly.

CREATE TABLE students (id INTEGER, name TEXT, class_id INTEGER);
CREATE TABLE classes (id INTEGER, class_name TEXT);
CREATE TABLE teachers (class_id INTEGER, teacher_name TEXT);

INSERT INTO students VALUES (1, 'Alice', 1);
INSERT INTO classes VALUES (1, 'Class A');
INSERT INTO teachers VALUES (1, 'Mr. Smith');

SELECT students.name, classes.class_name, teachers.teacher_name
FROM students
JOIN classes ON students.class_id = classes.id
JOIN teachers ON classes.id = teachers.class_id;

OUTPUT

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