joining three tables together using Inner Joins - sql

Question

Using Table aliases, list the first name, last name and start date of students enrolled on the java fundamentals module:
I am having some trouble when running the query below.
SELECT stu.StudFName, stu.StudLName, enrol.StartDate
From Student stu
INNER JOIN Enrolment enrol
ON stu.StudID = enrol.StudID
INNER JOIN Module mod
ON enrol.ModCode = mod.ModCode
WHERE mod.ModName = 'Java Fundamentals'
Structure:
CREATE TABLE Student
(StudID INTEGER PRIMARY KEY,
StudFName VARCHAR(10) NOT NULL,
StudLName VARCHAR(10) NOT NULL,
DoB DATE NOT NULL,
Sex CHAR(1) NOT NULL CHECK (Sex IN ('M', 'F')),
Email VARCHAR(30) UNIQUE);
CREATE TABLE Staff
(StaffID INTEGER PRIMARY KEY,
Title VARCHAR(4) CHECK (Title IN ('Prof', 'Dr', 'Mr', 'Mrs', 'Miss')),
StaffFName VARCHAR(10) NOT NULL,
StaffLName VARCHAR(10) NOT NULL,
Email VARCHAR(30) UNIQUE,
Department VARCHAR(25) DEFAULT 'Not Assigned',
Extension INTEGER CHECK (Extension BETWEEN 0001 AND 9999));
CREATE TABLE Module
(ModCode CHAR(4) PRIMARY KEY,
ModName VARCHAR(25) NOT NULL,
ModCredits INTEGER NOT NULL CHECK (ModCredits IN (15, 30, 45, 60)),
ModLevel CHAR(3) NOT NULL CHECK (ModLevel IN ('UG1', 'UG2', 'UG3', 'MSc')),
ModLeader INTEGER NOT NULL,
Foreign Key (ModLeader) REFERENCES Staff (StaffID));
CREATE TABLE Enrolment
(ModCode CHAR(4) NOT NULL,
StudID INTEGER NOT NULL,
StartDate DATE NOT NULL,
PRIMARY KEY (ModCode, StudID),
Foreign Key (StudID) REFERENCES Student (StudID),
Foreign Key (ModCode) REFERENCES Module (ModCode));

Answer 1

The answer is... there is no trouble with your query.
It works just fine.
Check here
INSERT INTO Student (StudID, StudFName, StudLName, DoB, Sex, Email) VALUES
(1, 'Jack', 'Black', TO_DATE('2015/01/01', 'yyyy/mm/dd'), 'M', 'jack#email.com');
INSERT INTO Student (StudID, StudFName, StudLName, DoB, Sex, Email) VALUES
(2, 'Andrew', 'Wiggin', TO_DATE('2015/01/01', 'yyyy/mm/dd'), 'M', 'andrew#email.com');
INSERT INTO Student (StudID, StudFName, StudLName, DoB, Sex, Email) VALUES
(3, 'Bob', 'Marley', TO_DATE('2015/01/01', 'yyyy/mm/dd'), 'M', 'bob#email.com');
INSERT INTO Staff (StaffID, Title, StaffFName, StaffLName, Email, Extension) VALUES
(1, 'Prof', 'Joe', 'Smith', 'stuff#emal.com', 0001);
INSERT INTO Module (ModCode, ModName, ModCredits, ModLevel, ModLeader) VALUES
(1, 'Java Fundamentals', 30, 'UG1', 1);
INSERT INTO Module (ModCode, ModName, ModCredits, ModLevel, ModLeader) VALUES
(2, 'C# Fundamentals', 15, 'UG2', 1);
INSERT INTO Enrolment (ModCode, StudID, StartDate) VALUES
(1, 1, TO_DATE('2015/01/01', 'yyyy/mm/dd'));
INSERT INTO Enrolment (ModCode, StudID, StartDate) VALUES
(1, 2, TO_DATE('2015/01/02', 'yyyy/mm/dd'));
INSERT INTO Enrolment (ModCode, StudID, StartDate) VALUES
(2, 3, TO_DATE('2015/01/03', 'yyyy/mm/dd'));
-------------------------------------------------------------
SELECT stu.StudFName, stu.StudLName, enrol.StartDate
From Student stu
INNER JOIN Enrolment enrol ON stu.StudID = enrol.StudID
INNER JOIN Module mod ON enrol.ModCode = mod.ModCode
WHERE mod.ModName = 'Java Fundamentals'
Result
STUDFNAME STUDLNAME STARTDATE
----------------------------------------
Jack Black January, 01 2015
Andrew Wiggin January, 02 2015