Create view oracle sql - sql

Question

I am making a database with tv-shows and users.
These users can follow each other and are saved in the database by an UserID.
Now I wan't to create a view with the names of the users instead of the UserID's.
--Drop all tables.
DROP TABLE Series CASCADE CONSTRAINTS;
DROP TABLE User1 CASCADE CONSTRAINTS;
DROP TABLE FollowingSeries CASCADE CONSTRAINTS;
DROP TABLE FollowingUser CASCADE CONSTRAINTS;
DROP TABLE Episode CASCADE CONSTRAINTS;
DROP TABLE Watched CASCADE CONSTRAINTS;
DROP VIEW Test CASCADE CONSTRAINTS;
--Create all tables.
CREATE TABLE Series
( SeriesID NUMBER(5) primary key,
Name VARCHAR2(100) NOT NULL,
Status VARCHAR2(20),
Premiered DATE,
Genre VARCHAR2(100),
Country VARCHAR2(100),
Network VARCHAR2(100),
Runtime VARCHAR2(25)
);
CREATE TABLE User1(
UserID NUMBER(5) primary key,
Username VARCHAR2(100) NOT NULL,
Country varchar2(100),
Gender VARCHAR2(10),
Birthday VARCHAR2(100),
About_me VARCHAR2(300),
Password VARCHAR2(100) NOT NULL
);
CREATE TABLE FollowingSeries (
UserID NUMBER(5) NOT NULL,
SeriesID NUMBER(5) NOT NULL,
Ignore1 CHAR(1) DEFAULT 0,
constraint FollowingS_pk primary key(UserID, SeriesID),
constraint FollowingS_fk1 foreign key(UserID) REFERENCES User1(UserID),
constraint FollowingS_fk2 foreign key(SeriesID) REFERENCES Series(SeriesID)
);
CREATE TABLE FollowingUser (
UserID1 NUMBER(5) NOT NULL,
UserID2 NUMBER(5) NOT NULL,
constraint FollowingU_pk primary key(UserID1, UserID2),
constraint FollowingU_fk1 foreign key(UserID1) REFERENCES User1(UserID) ON DELETE SET NULL,
constraint FollowingU_fk2 foreign key(UserID2) REFERENCES User1(UserID) ON DELETE SET NULL
);
CREATE TABLE Episode(
SeriesID NUMBER(5) NOT NULL,
Season NUMBER(2) NOT NULL,
Episode NUMBER(2) NOT NULL,
Name varchar2(100) NOT NULL,
Airdate DATE,
Summary varchar2(1500),
constraint episode_pk primary key(SeriesID, Season, Episode),
constraint episode_fk foreign key(SeriesID) REFERENCES Series(SeriesID) ON DELETE SET NULL
);
CREATE TABLE Watched(
UserID NUMBER(5) NOT NULL,
SeriesID NUMBER(5) NOT NULL,
Season NUMBER(2) NOT NULL,
Episode NUMBER(2) NOT NULL,
constraint watched_pk primary key(UserID, SeriesID, Season, Episode),
constraint watched_fk1 foreign key(UserID) REFERENCES User1(UserID),
constraint watched_fk4 foreign key(SeriesID, Season, Episode) REFERENCES Episode(SeriesID, Season, Episode)
);
--Add users.
INSERT INTO User1 VALUES (1, 'StefPhilipsen', 'Netherlands', 'Male', TO_DATE('02-01-1994','DD-MM-YYYY'), 'Ik ben Stef', 'abcd1234');
INSERT INTO User1 VALUES (2, 'Dorothy142', 'America', 'Female', TO_DATE('01-10-1963','DD-MM-YYYY'), 'I love mountainbiking', 'Oow6sai4Ie');
INSERT INTO User1 VALUES (3, 'Rudo12', 'England', 'Male', TO_DATE('05-6-1985','DD-MM-YYYY'), 'I watched Breaking Bad and a lot more', 'Oph9Ge2yai');
INSERT INTO User1 VALUES (4, 'JohnSmith', 'England', 'Male', TO_DATE('27-9-1945','DD-MM-YYYY'), 'I like potatoes.', 'phiShaip0c');
INSERT INTO User1 VALUES (5, 'EulaWGibson', 'America', 'Female', TO_DATE('12-8-1990','DD-MM-YYYY'), 'I''m Eula. I live in massachusetts and I''m happily married with my husband Hank.', 'EiM5wii2am8');
INSERT INTO User1 VALUES (6, 'Pedro', 'Spain', 'Male', TO_DATE('12-10-1945','DD-MM-YYYY'), 'I love watching Arrow.', 'Gith0yaiw');
INSERT INTO User1 VALUES (7, 'TravisC', 'England', 'Male', TO_DATE('12-7-1970','DD-MM-YYYY'), 'My favorite TV-shows are Modern Family and Dexter.', 'gie9aiPh2Ii');
INSERT INTO User1 VALUES (8, 'DonellaScott', 'America', 'Female', TO_DATE('31-1-1996','DD-MM-YYYY'), 'Living the life.', 'Gued1996');
--Who follows which series.
INSERT INTO FollowingSeries(UserID, SeriesID) VALUES (1,1);
INSERT INTO FollowingSeries(UserID, SeriesID) VALUES (1,2);
INSERT INTO FollowingSeries(UserID, SeriesID) VALUES (1,3);
INSERT INTO FollowingSeries VALUES (1,4,1);
--Who follows who.
INSERT INTO FollowingUser VALUES(1,2);
INSERT INTO FollowingUser VALUES (2,3);
INSERT INTO FollowingUser VALUES (3,4);
INSERT INTO FollowingUser VALUES (1,3);
INSERT INTO FollowingUser VALUES (5,8);
INSERT INTO FollowingUser VALUES (5,6);
INSERT INTO FollowingUser VALUES (6,5);
-- Which episodes are watched by whom.
INSERT INTO Watched VALUES(1, 4, 1, 1);
INSERT INTO Watched VALUES(1, 4, 1, 2);
INSERT INTO Watched VALUES(1, 4, 1, 3);
INSERT INTO Watched VALUES(1, 4, 1, 4);
INSERT INTO Watched VALUES(1, 4, 1, 5);
INSERT INTO Watched VALUES(1, 4, 1, 6);
INSERT INTO Watched VALUES(1, 4, 1, 7);
This is what I tried but then I get an error message
--Create view
CREATE VIEW follownaam AS
SELECT followerUser.Username AS Follower, followingUser.Username AS Following
FROM FollowingUser AS fu
INNER JOIN User1 followerUser ON(fu.UserID1 = followerUser.Username)
INNER JOIN User1 followingUser ON(fu.UserID2 = followingUser.Username)
WHERE fu.UserID1 = 1;
[Err] ORA-00911: invalid character
The table I have exists of 2 UserID's. But now I want exactly the same table, but this view must contain the Usernames of these UserID's.

Answer 1

This should work (although i don't understand why You want a view only for user with ID = 1).
CREATE VIEW follownaam AS
SELECT
followerUser.Username AS Follower, followingUser.Username AS Following
FROM FollowingUser fu
INNER JOIN User1 followerUser ON(fu.UserID1 = followerUser.UserID)
INNER JOIN User1 followingUser ON(fu.UserID2 = followingUser.UserID)
WHERE fu.UserID1 = 1;
I changed Username to UserId because it made much more sense.
Edit:
Here's sqlfiddle i created to test it and it works.