Wo steckt nur der Fehler in der SQL-Anfrage?

I. Saatz, “Where Is the Error in the SQL Query?,” in Automatic Evaluation of Programming Tasks: ABP 2017: Proceedings of the Third Workshop “Automatic Evaluation of Programming Tasks” (ABP 2017): Potsdam, Germany, October 5–6, 2017, Aachen: RWTH Aachen, 2017, pp. 1–9. Available: https://ceur-ws.org/Vol-2015/