ERM, Generalization, Specialization, supertype,subtype, discriminator, TODO
Elemente des ER-Modells (Generalisierung/Spezialisierung)
Slide/ER Model IsA# QUERY5e1b02f2a5b6712e69e022476f1cb0bf
Slide/ER Model IsA# ae3bcafc71cd6026f8fcdbe393d261d9