Joins on multiple tables in Postgresql - sql

Question

I'm practising for an upcoming database exam and I'm trying to get my head around nested and multiple joins in SQL, specifically the Postgresql syntax. I want to return all the student names and department names of all students that achieved grade A.
Here's my schema.
CREATE TABLE student1 (
student_number INTEGER NOT NULL PRIMARY KEY,
name TEXT NOT NULL,
class INTEGER NOT NULL,
major TEXT NOT NULL
);
CREATE TABLE course1 (
course_name TEXT NOT NULL,
course_number TEXT NOT NULL PRIMARY KEY,
credit_hours INTEGER NOT NULL,
department TEXT NOT NULL
);
CREATE TABLE section1 (
section_identifer INTEGER NOT NULL PRIMARY KEY,
course_number TEXT NOT NULL,
semester TEXT NOT NULL,
year INTEGER NOT NULL,
instructor TEXT NOT NULL,
FOREIGN KEY (course_number) REFERENCES course1(course_number) ON DELETE CASCADE
);
CREATE TABLE grade_report1 (
id SERIAL NOT NULL PRIMARY KEY,
student_number INTEGER NOT NULL,
section_identifer INTEGER NOT NULL,
grade TEXT NOT NULL,
FOREIGN KEY (student_number) REFERENCES student1(student_number) ON DELETE CASCADE,
FOREIGN KEY (section_identifer) REFERENCES section1(section_identifer) ON DELETE CASCADE
);
I put together a nested statement that I thought would work:
SELECT t1.name, t3.department
FROM (student1 t1 INNER JOIN grade_report1 t2 ON t1.student_number = t2.student_number) t5
INNER JOIN (course1 t3 INNER JOIN section1 t4 ON t3.course_number = t4.course_number) t6
ON t5.section_identifer = t6.section_identifer
WHERE t2.grade = 'A';
However, this gives me the error invalid reference to FROM-clause entry for table "t1". I'm guessing it is because that is not how you are supposed to name/reference JOINS. I would like a way to JOIN all of these tables together. Thanks!

Answer 1

Remove the parentheses and fix the aliases:
SELECT s.name, c.department
FROM student1 s INNER JOIN
grade_report1 gr
ON gr.student_number = s.student_number INNER JOIN
section1 sec
ON sec.section_identifer = gr.section_identifer INNER JOIN
course1 c
ON sec.course_number = c.course_number
WHERE gr.grade = 'A';
The parentheses are allowed, but they are not needed. When using parentheses (which is very, very rarely needed), they do not get separate aliases.