Cant create table ..... (erno: 150)

Databases
1

Well morning everybody,

so actually i have to do some work for my coming classtest, everything is working fine … just the last part of my sql script.


CREATE DATABASE IF NOT EXISTS db_schueler;
USE db_schueler;

CREATE TABLE IF NOT EXISTS tbl_schueler (
			id INT(4) NOT NULL AUTO_INCREMENT,
			name CHAR(12) NOT NULL,
			vorname CHAR(12) NOT NULL,
			adresse char(50) NOT NULL,
			stadt CHAR(20) NOT NULL,
			versetzung12 BIT NOT NULL,  -- 1/0 bzw. Ja/Nein
			PRIMARY KEY (id)
			);
			
CREATE TABLE IF NOT EXISTS tbl_fach (
			fach_id INT(4) NOT NULL AUTO_INCREMENT,
			tbl_schueler_id INT(4),
			deutsch CHAR(12) NOT NULL,
			mathe CHAR(12) NOT NULL,
			englisch CHAR(12) NOT NULL,
			datenbank CHAR(12) NOT NULL,
			programmiertechnik CHAR(12) NOT NULL,
			betriebnetzwerke CHAR(12) NOT NULL,
			PRIMARY KEY (fach_id),
			FOREIGN KEY (tbl_schueler_id) REFERENCES tbl_schueler(id)
			);
			
CREATE TABLE IF NOT EXISTS tbl_zensuren (
			zensuren_id INT(4) NOT NULL AUTO_INCREMENT,
			schueler_versetzung12 BIT NOT NULL,  -- 1/0 bzw. Ja/Nein
			prüfung BIT NOT NULL, -- 1/0 bzw. Ja/Nein
			PRIMARY KEY(zensuren_id),
			FOREIGN KEY(schueler_versetzung12) REFERENCES tbl_schueler(versetzung12)
			);

I am getting this Error Cant Create table ‘db.schueler.tbl_zensuren’ (erno: 150)
I Found out that this error stays in connection with the foreign key, but i have no idea.

I Hope s.o can help me to fix this.

Grettings

2

a foreign key must reference either a primary or unique key, i believe

also, what would be the purpose of declaring a 1/0 column as a foreign key?